Black Screen at booting with Live CD at autoconfiguring X

[Wishes]

Hello
I got the same problem since Fedora 6 i think, is also happens a long time with other distros, but with most of them, i works now in the newer versions (Ubuntu after 7.04, Mepis, Mandriva, in Arch it always worked fine).

It boots fine til it tries to autoconfigure X. Then the screen goes black and says no signal. Ctrl+Alt+F1-6 doesnt work, no screen. Also Ctrl+Alt+Del doesnt work, i have to push the reset button.

Hardware is a AGP 1950Pro on a NForce 2 Motherboard (Abit NF7S). Monitor is a FSC P19-2 connected through DVI (i tried analog connection, same problem).

i tried several boot options i found (lowres, nofb, skipddc, text, rescue, remove quiet and the rghb thing, liveinst, vga=795)

i cant get to any console to manualy edit the xorg.conf, i cant install the system...
I am at limited bandwith here, so downloading the DVD is not really an option.

Any ideas?

[Wishes]

ok, i manage to get in a VT (add 3 to the boot line in grub), then i logged in into root and "Xorg -configure". Now i got a new xorg.conf.new, which i edited with nano and changed the driver from radeon to vesa. After that i started gdm, and it works, i log in, but then only the wallpaper is shown and nothing happens. In the VT i got the message that the gnome-session is not started, and when i trie to start it, it says it cannot open a display.

[Wishes]

ok, i can start gnome-session and liveinst with "DISPLAY=:0 gnome-session" as root and user with X running (no gdm, just X).

Next problem is, i want to use ext4 as filesystem, but the installer doesnt give me that option: even if i add "ext4" in grub as bootoption.