>Do you mean that it happens *every time* for those two users ?
>
>To the best of my knowledge - yes. It happens to them every time and no one else can make it happen.
>
>Any reason to believe they may be doing something differently?
>
>I have been trying my best to reporoduce the behavior - unsuccessfully...
>
>Shot in the dark : An exception that bubbles up and is then swallowed....
>
>Hmmmm. Possible but I doubt it. I have a global error handler in place for just those occassions where something gets by the local try - catch blocks. And my try catch blocks always display something in the catch.

I admit I also thought it unlikely. Sounds as if Joel may have been on the right track tho'. If double clicking can close the *entire* app then obviously it also closes the dialogs parent window - maybe just that, in *some* scenarios, it also goes on to close the main window?