Please Install the Updated Packages.
The via driver originally available in Xorg on 2007.0 has an unresolved symbol that lead the X server to crash. The problem could be reproduced on any hardware the driver supports simply by starting the X server. The updated driver fixes this specific problem by making all the symbols resolved.
x11-driver-video-via on Mandriva Linux 2007.0, Mandriva Linux 2007.0/X86_64