I have 20 PCs (Windows XP) in remote locations connecting to the same server (Windows Server 2003) using Remote Desktop over a VPN. On just one of the PCs the remote desktop screen flashes (redraws) multiple times after connecting, the others don't. The screen resolution is the same: local is 800x600 32bit; RDP file is set to full screen, 256 color; remote when connected is 800x600 8bit color.
Any suggestions what the problem might be, or what to investigate next?