I also have a GA-EP45-DS3L and I may also be having video issues with chameleon 2.0 RC 1 (r431) on Vanilla OS X 10.5.7. My video card is an nvidia 8800GTX and I enable it with device-property string in the Boot.plist, attached below.
I cannot boot without setting "Boot Graphics"=Yes. No amount of -x, -v, -F can save me from the near instant white rectangle of death in the upper left hand ceiling of my screen. I've tried various "Graphics Mode" settings to no avail. Safe mode (-x) flashes the text loading that it normally does, but when it goes to switch resolution the white box of death appears. Verbose mode (-v) flashes no text after the bootloader prompt, but goes immediately to the white box of death, though it may flicker a moment before sticking.
However, if I enable "Boot Graphics", then I can boot. This is not good, because I am unable to debug any other issues in the boot process. Namely, my now dead HDA, which was good on my last install of 10.5.6 with munky EFI partition.
Cheers!
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>Kernel</key>
<string>mach_kernel</string>
<key>Kernel Flags</key>
<string></string>
<key>GUI</key>
<string>No</string>
<key>Boot Graphics</key>
<string>Yes</string>
<key>Timeout</key>
<string>2</string>
<key>device-properties</key>
<string>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</string>
</dict>
</plist>