Alright, here it is:
When loading a level, the loading bar gets to nearly full... then the system completely locks up.

Not regularly reproducible: savegames immediately before a level transition with a scripted sequence don't crash - possibly because the autosave doesn't happen in that case. However, when it DOES happen, it's a complete system lockup and requires a hard reset.

Obvious solution: Disable autosave, save manually and often.

System specs:

AMD Athlon 64 3200+
Radeon 9600 256MB
512 MB DDR400

[Just to clarify: TSL, not KotOR.]