My program consists of several dlls. Each of them instantiates the clsCommonWrapper and other frequently used classes in a central module. Up to now I never set those instances to "nothing" when terminating instances of my dll-classes. (Im am currently investigating, why I get more and more often the message "...doesn't respond anymore" - either for my program or for the VB-IDE - when I close a window.) Do you have any suggestion, where to set instances to nothing, which I instantiated in a sub main?