Meanwhile i've found several weird bugs using VB8/VS8 Professional w/SP1 Here a screenshot while debugging some code. If you look at the yellow line that shows the current position in code and look at the fly over window that tells the contents of the "throwEx" variable then you'll see what i mean: Evaluation of the condition is wrong. I have the suspicion that this is caused by severe pointer bugs in SimConnect which causes the process memory to be corrupted. I couldn't reproduce this phenomenon in a small test project, but i have at least one more case where something like that happens in FSCareer. The error doesn't happen in the release version of FSCareer but that says nothing since the corrupted memory just shifts to another location in memory which might produce other random bugs that i didn't discover yet. Anyone here with similar observations?