A: 

There was a change in how unhandled exceptions were treated on threads between v1.1 and v2.0 of .Net. It sounds like on your machine, the v1.1 model is being used, where the exception is swallowed. Do you have the tag <legacyUnhandledExceptionPolicy enabled='1'/> in your machine.config or app.config file?

codekaizen
@jrista in my local, the application continues...@codekaizen the app.config is the same in both, client and my local.. and there isn't any legacyUnhandledExceptionPolicy... the machine.config applies to winforms?thanks for your help
Osvier
@user - the machine.config file applies to _everything_ in .Net on that machine.
codekaizen
oh ok, well, I have checked the machine.config and there isn't any "legacyUnhandledExceptionPolicy"... This error starts becoming even worst... I could replicate the pop up message...but the second time I try to do it... didn't work... I have tried like 5 more times... and I CAN'T get the error message again :s
Osvier
Do you have an event handler attached to `AppDomain.Current.UnhandledException`?
codekaizen
Actually I've just added the code to catch the unhandled error... the weird thing is why in the client the same application same version same configurations... is throwing me an error that is not happening in my dev computer... anyway as you say, with the AppDomain.Current.UnhandledException I should be able to catch any error... Thanks...http://msdn.microsoft.com/en-us/library/system.windows.forms.application.setunhandledexceptionmode.aspx
Osvier