Interesting. This crash is occuring down in the Windows OLE automation library, which is what oleaut32.dll is. It is essentially a bug in Windows. Such crashes should never happen in theory in that argument checking should prevent any non-malicious app like DB from being able to crash the DLL. The error dialog is being thrown up by Windows itself, bascially saying "whoops, some application called darwin2.43x.exe made a call into me and I crashed and hosed it. So sorry, I hope you saved - that is, if the app is the type of app that has anything to save, it could be anythign for all I know - because your probably screwed".
The DB thread is probably making some call into that DLL, perhaps to do file I/O to save lastexit.sim or delete the internet mode population file or similar (I forget all thats in that DLL) and indirectly causing the crash by passing it some argument that indrectly causes the crash. Don't ask me how exactly. Your disk isn't full, is it? Perhaps lastexit.sim is already open - you don't have any hung zombie instances of db still running, do you? (check via the task manager). Were you running interent mode when you exited? Does it only happen at exit time? Does it happen every exit? Is your machine up to date (I.e. do you have Windows Update turned on and is your Windows code current?).
All that technical data could tell me exactly how and where in the Windows DLL the crash occurred, but it would take a lot of detective work to trace it back up into the DB code were I could fix it or rather, change DB's behaviour so as not to cause it. Best bet is to try and narrow down the circumstances and look for a repro case. I doubt it has anything to do with your specific sim. Probably has more to do with exiting while in internet mode or when lastexit.sim is locked by a zombie process or something like that.