You could install Filemon and use it to see what files it's accessing right before crashing.

Please also try to run vanilla RTW in the given installation to verify that that is running without problem.

Just in case, you should try the oasis temporary fix too, but I don't really think this is the problem as most have got error messages about it while you get none.

You may want to check your RAM using Memtest (google it) overnight if the game is crashing at erratic times. It will suggest solutions if there is a problem.