Version:            (using KDE KDE 3.2.3)
Installed from:    Gentoo Packages
Compiler:          gcc 3.3.3 
OS:                Linux

After logging in, the first time Alt-F2 is pressed to bring up the Run Command dialog causes the desktop image to become 'stuck' on whichever virtual desktop was active at the time.  (For example, if I was on Desktop 3 and pressed Alt-F2, from that point on the background will show Desktop 3's image even if I change to another virtual desktop with a different image.)  Furthermore, if at any time afterwards the Run Command dialog is invoked, it will appear on that same desktop regardless of which one is currently active.

Neither changing the desktop settings nor refreshing causes any change, although it 'resets' to the correct behavior upon logging out and then back in.  If it helps, I obtained and compiled KDE from the Gentoo portage tree, using Qt 3.3.2.