Attempted to read or write protected memory when opening new form

[djpaul]

Hello!
I am getting this error when i open a new form into antoher form.
System.AccesVio lationException - Attempted to read or write protected memory.

What i do is :

Dim PrintView as new PrintForm()
PrintView.ReportName = "SaleView"
            PrintView.GetPaymentChoice = Data
            PrintView.GetQuery = Query
            PrintView.Show(Me)

This only happens when i developing my app on windows 7. On my other computer (win xp) it works just fine!
Is there a workarround for it or is there another problem?

Thanks!
Paul