CTD at about 95% loaded on career on both my systems.
System 1:
Win 7 64 bit,
i7 920 CPU
6 GB RAM
GTS 250 graphics card
Steam version of SH3 - fresh install
System 2:
Win XP 32 bit
AMD Athlon 64 X2 dual core
2 GB RAM
nvidia 8500 graphics card
DVD version of SH3 - fresh install
The only mods I had loaded were GWX 3 with the 16 km visuals and the no medals on crew options activated.