fc7t1- gdm crash and keep getting blank screen

["yonas Abraham" <yabraham2 gmail com>]

I installed fc7t1 on my dell dimension 4300 with 17 in flat screen,
and randomly I got a black/blank screen after boot or after I log out
instead of the nice gdm greater. I have to hit Ctrl+Alt+Backspace to
restart it. Some times it works after just one try but some times I
have to try it several time. should I file a bug report against xorg
or gdm?

lspci report the graphics as:
Display controller: Intel Corporation 82915G Integrated Graphics
Controller (rev 04)

any help?