This issue occurs because the non-administrator user account cannot access the %WINDIR%\System32 folder. By default, WPF writes the output file to the %WINDIR%\System32 folder. The %WINDIR%\System32 folder requires administrator permissions. When the non-administrator account tries to access this folder, the WPF caching code is triggered. This code causes the screen to flicker.
In 32-bit versions of the Windows Server 2003 operating system, the output file is D3d9caps.dat. In 64-bit versions of the Windows Server 2003 operating system, the output file is D3d9caps64.dat.
To resolve see http://support.microsoft.com/kb/955692