when do the blank screen appear?
there are 3 main possibilities:
1. when the kernel loads the framebuffer (just after the bios checkt the system)
2. when modprobe loads the driver
3. when you start x
for me it seems to be your kernel framebuffer.. do you have any kernel flags in your bootloader? something like vga=XXX or vga=0xXXXX? if yes set this to vga=ask, then will (in my case lilo) your bootloader ask your grafic card which resolution you could use or which are supported.
in my case there is a problem with my tv-out. it is always on, also when no cable is pluged in so the highest resolution is 720x400..
if i set a higher resolution like vga=791 (i think 1024x768x16) the screen is blank untill x server started and the settings from my XF86Config are loaded
hope i could help you