RemoteApp - Moving forms leaves artifacts

When using our application via a deployed RemoteApp when we move forms around it leaves an artifact of the form on the screen.  Any ideas?

Server --> Windows 2008 R2
Clients --> Windows 7, Windows XP

The problem does not happen when the application is run on the desktop.
The problem does not happen when the application is delivered via Citrix.

I would like to provide more information but do not know what else is relevant.