Problems switching KDE - Console

[Crash1976M]

Hi
i have here installed the rc1 with kde ...
but when i just logged on kdm (for kde) and will switch to one of the console to log on there while kde is loading/initializing, kde is imidiatly closing the x session and kdm retourns. also the console session stop after the user: root und the screen jumps to the kdm section.

if i wait to log on on kde incl. loading/initializing, then i can switch without any problems.
i have here a Radeon ATI

/proc/pci:
Bus 1, device 0, function 0:
VGA compatible controller: ATI Technologies Inc Radeon QL (rev 0).
IRQ 11.
Master Capable. Latency=64. Min Gnt=8.
Prefetchable 32 bit memory at 0xd0000000 [0xd7ffffff].
I/O at 0x9800 [0x98ff].
Non-prefetchable 32 bit memory at 0xdfef0000 [0xdfefffff].

/etc/X11/XF86Config
Section "Device"
Identifier "Ati Radeon"
Driver "vesa"
#VideoRam 65536
# Insert Clocks lines here if appropriate
EndSection

Does anyone have the same problems in this configuration ???