OpenDialog, SaveDialog and Common Dialogs Problem

Dear All,

I have a intermittent problem occuring on different WIN95 machines.
The problem is that the OpenDialog.Exceute fails to work. In the
application when trying to save and load, the code is executed and does not
show the Dialog on the screen.
When this occurs it seems that all the Common Dialogs (Printer Setup, Save)
Fail to work.
This problem happens about a few times a day but can be very annoying when
work cannot be saved.

Please Help with some suggesions , has anyone else encountered this