game crashes back to destop at end of turn

[Ron35]

hi there all u civ 4 players,
i've been having the same problem over and over again. during the tutorial,
(sid meier has allready finished his monotonous explanation for a while) at the end of a turn i hit enter and it shuts back to desktop, not leaving a message or anything. it allways happens at the and of the same turn.
i allready installed latest ati-cataclyst drivers (radeon 9600). but doesn't work. dunno what to do next. can anyone help me out here?
system:XP SPII on PIV 2800GHz 256 MB VID 512 MB DDR

 

[crunch]

Does this happen on 10th turn?

 

[Ron35]

i dunno exactly where i can find the number of the turn but i guess it must be over turn 10 cause i'm in the year 300 AD.