I am using VB.NET 2003. My project is working, but time to time displaing an error;

An unhandled exception of type 'System.OutOfMemoryException' occurred in system.windows.forms.dll
Additional information: Error creating window handle.

After restart the Windows this is OK, but after running the project few times, Error raises again.

Always error is raised at a form opening point. That code is below,

Dim frm4 As New Form4
frm4.MdiParent = MdiParent
frm4.Show()
Me.Close()

What can i do this? Should we manually open the garbage Collection?
Please help me. I am a MSc Student and I have to submit my project before end of this month.
Thanks,

Dimuthu