KDE Starts-and then X Server stops

[Strop Alexander <alexander.strop@siemens.com>]

Hi,

I installed Debian woody and was sucessful installing X with your Help and
apt-get.

Pc:

P4
ATI Radeon 9000
500MB Ram

I tried the ATI Xserver but it doesn't work. Then i tired VESA. I configured
DE Keyboard, PS/2 Mouse and nodeadkeys.
If i type "startx"

The x Server starts, then The KDE Logo appears and then the first icon on
the logo seems to be ok. 
Then the second icon blinks and suddenly X crashed.

What could it bee?

Sorry for my bad english.

Alex