Dispose called in Form

We have a Form based application,开发者_Go百科 which contains user controls in tabs. One of the user control has a grid. A popup is displayed to modify certain values of the grid. If we click the OK button of the popup, Dispose is called on the Form. The problem is present in Win Xp 64 bit. It is working fine in WIn XP 32 bit.

How can I know that which portion is calling Dispose of the Form? How can I correct the issue?

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You can find out who calls Dispose() on your form by setting a breakpoint on the Dispose() method of your form, attach the debugger, click at on the OK button and when the breakpoint gets hit look at the callstack.