Debug version is updated, boot menu always shows up, with mode dimensions and framebuffer address (the last is for ATI).
There is a possible fix for weird nVidia dimensions. It consists in calling setVBEmode with a VBECRTCInfoBlock structure properly filled with our calculated timings, with Interlace and DoubleScan flags off. I added Horizontal Sync Negative, but it doesn't change a thing for me.
I hope there is some change in the good direction.