Presario 900z unreal tournament?

[vToMadness]

hey guys, i got a presatio 900z laptop recently, was wondering if there is any reason that unreal tournament runs REAL fast, and sometimes shuts down, ive tried changing the rendering device and the resolution, no go. here are my specs

athlon xp 1500+
768MB pc2100
radeon mobility (from what i was told) im using u1 drivers tho.

any suggestions?

also, my escape key does not work within windows, but it does work in the bios. any suggestions?

any help would be GREATLY appreciated!!!
thanks so much!