You might check out this thread:
http://www.displaylink.org/forum/showthread.php?p=74637
I suggested running the following commands in terminal to basically disable the animation that takes place when showing the desktop/exposé:
Code:
MyCompy:~$ defaults write com.apple.dock expose-animation-duration -float 0
MyCompy:~$ killall Dock
I haven't had a Window Server crash since setting the animation duration to 0 (nearly a month now). Hope that helps!