Some interesting information for anyone having the same rig as mine, and SWBF2 crashing:
"Playing the game on a dual core processor (AMD X2) will make it crash and the NVIDIA GeForce 7800 GTX (SLI enabled) is not compatible with SWBFII.
These problems are noticed and will be solved with the first coming patch. Unfortunately there is no further info about when this will be released."
This I got from another forum from someone called Katootje.