Two more issues:
a) the System Profiler shows no audio interface being present, even though obviously it is, and it mostly works
b) every now and then, there's a short period of static, almost as if buffers were overrun or something like that, and then it recovers. It's not a big deal when using Skype or such, but it's a nuisance when listening to iTunes because you never know if your audio files are corrupt, or if it's just the driver going funky.
Here an excerpt from the system.log when things go bonkers:
2009-05-30 03:09:38 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (13de,8f8)->(13df,10fa).
2009-05-30 03:09:38 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - adjusting clipped position to (13df,8f8)
2009-05-30 03:09:38 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (13e1,8fa)->(13e2,1105).
2009-05-30 03:09:38 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - adjusting clipped position to (13e2,8fa)
2009-05-30 03:09:38 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (13e3,905)->(13e4,1110).
2009-05-30 03:09:38 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - adjusting clipped position to (13e4,905)
2009-05-30 03:09:38 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (13e5,910)->(13e6,111f).
2009-05-30 03:09:38 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - adjusting clipped position to (13e6,910)
2009-05-30 03:09:38 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (13e7,91f)->(13e8,112f).
2009-05-30 03:09:38 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - adjusting clipped position to (13e8,91f)
2009-05-30 03:09:38 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (13e9,92f)->(13ea,1140).
2009-05-30 03:09:38 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - adjusting clipped position to (13ea,92f)
2009-05-30 03:09:38 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (13eb,940)->(13ec,1151).
2009-05-30 03:09:38 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - adjusting clipped position to (13ec,940)
2009-05-30 03:09:38 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (13ed,951)->(13ee,115f).
2009-05-30 03:09:38 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - adjusting clipped position to (13ee,951)
2009-05-30 03:09:38 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (13ef,95f)->(13f0,116f).
2009-05-30 03:09:38 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - adjusting clipped position to (13f0,95f)
2009-05-30 03:09:38 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (13f1,96f)->(13f2,1178).
2009-05-30 03:09:38 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - adjusting clipped position to (13f2,96f)
2009-05-30 03:09:38 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (13f3,978)->(13f4,1185).
2009-05-30 03:09:38 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - adjusting clipped position to (13f4,978)
2009-05-30 03:09:38 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (13f5,985)->(13f6,1195).
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - adjusting clipped position to (13f6,985)
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (13f7,995)->(13f8,11a7).
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - adjusting clipped position to (13f8,995)
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (13f9,9a7)->(13fa,11b6).
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - adjusting clipped position to (13fa,9a7)
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (13fb,9b6)->(13fc,11c2).
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - adjusting clipped position to (13fc,9b6)
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (13fd,9c2)->(13fe,11cc).
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - adjusting clipped position to (13fe,9c2)
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (13ff,9cc)->(1400,11db).
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - adjusting clipped position to (1400,9cc)
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (1401,9db)->(1402,11e9).
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - adjusting clipped position to (1402,9db)
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (1403,9e9)->(1404,11f9).
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - adjusting clipped position to (1404,9e9)
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (1405,9f9)->(1406,1205).
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - adjusting clipped position to (1406,9f9)
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (1407,a05)->(1408,1210).
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - adjusting clipped position to (1408,a05)
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (1409,a10)->(140a,121f).
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - adjusting clipped position to (140a,a10)
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (140b,a1f)->(140c,122c).
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - adjusting clipped position to (140c,a1f)
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (140d,a2c)->(140e,123d).
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - adjusting clipped position to (140e,a2c)
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (140f,a3d)->(1410,124d).
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - adjusting clipped position to (1410,a3d)
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (1411,a4d)->(1412,125c).
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - adjusting clipped position to (1412,a4d)
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (1413,a5c)->(1414,126a).
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - adjusting clipped position to (1414,a5c)
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (1415,a6a)->(1416,1279).
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - adjusting clipped position to (1416,a6a)
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (1417,a79)->(1418,1286).
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - adjusting clipped position to (1418,a79)
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (1419,a86)->(141a,1290).
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - adjusting clipped position to (141a,a86)
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (141b,a90)->(141c,12a0).
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - adjusting clipped position to (141c,a90)
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (141d,aa0)->(141e,12ad).
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - adjusting clipped position to (141e,aa0)
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (141f,aad)->(1420,12bf).
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - adjusting clipped position to (1420,aad)
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (1422,abf)->(1423,12cc).
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - adjusting clipped position to (1423,abf)
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (1424,acc)->(1425,12d8).
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - adjusting clipped position to (1425,acc)
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (1427,ad8)->(1428,12e4).
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - adjusting clipped position to (1428,ad8)
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (142a,ae4)->(142b,12ed).
2009-05-30 03:09:39 kernel IOAudioStream[0x4b85a00]::clipIfNecessary() - adjusting clipped position to (142b,ae4)