Strange form behavior

[SanganakSakha]

On each of my form I have put an 'Exit' button. When user clicks it, another
form is displayed (I don't want to use 'MessageBox') asking user whether he
really wants to quit. If user clicks yes the form closes. If user clicks no,
form is redisplayed.

However, out of 4 forms only one form refuses to redisplay. The code is exactly same on all forms.

I have included 2 Express 2008 projects showing one form each in the zip file
apps-ssk.zip

Can somebody have a look at it and advise me how to overcome this problem?

I have spent 3 days but no success.