KDE menus slow to appear when using VNC, but OK local

[Lets Go Canes]

Hi all.

I am having a problem on a laptop where the KDE "kickoff application launcher" takes several seconds to appear after it is clicked - 30 to 40 seconds would be typical.  The same problem exists with the "lock screen" and "shutdown/logout" widgets that I have added to the taskbar.  The problem only occurs over VNC - it does not occur when logged-in to the laptop directly.

The problem would seem to be similar to the one discussed at http://forums.fedoraforum.org/showthread.php?t=234227 , with the following differences:
o problem occurs on a VNC display, but not on the laptop's LCD
o system uses the radeon driver, not nvidia
o system has xorg-x11-server-Xorg.i686 and xorg-x11-server-common.i686 1.7.4-1.fc12 installed (I tried 1.7.4-4, but it didn't fix the problem, and "broke" the laptop display)

Has anyone else seen anything similar, or have any suggestions?

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Lets Go Canes!