Window Crashing.Looking for cause

Hey all, I have a button that when pressed brings up the Insert Slides from File window.

[VBA]
Private Sub btnSelect_Click()
CommandBars("Insert").controls("Slides from Files...").Execute
End Sub
[/VBA]

It works. But if I press my button once and then close the insert window and then press the button again the Insert Slides from File window crashes. It just shows the bottom buttons, the top area is all greyed out and all options except close is disabled.

Does anyone have any ideas on what may cause this?

Thank You

No clues here. I can't replicate the problem. (PPT 2002 or 2003)
It might be worth posting an example in case there's something else in the mix that's causing it

Well what i'm doing is allowing the user to combine 2 presentations together. With doing that i have a few options. Two of those options are insert whole presentations or individual slides. Individual slides is where the Insert Slides from Files part comes in. The code snippet that I posted is all i have for that and when i run mine twice it crashes. But the normal way of doing it (going to insert>slides from files.) does not crash at all (so i know its not my computer).