Comment 2 for bug 174088

Hello. This is happening on a development box, I'm loathe to install dbg packages on it...I've subsequently discovered further information, hopefully, you may be able to track the bug down now?

I'm using sawfish with viewports:
% cat ~/.sawfishrc
(define-special-variable viewport-dimensions '(3 . 3) "Size of each virtual workspace.")

And this bug shows up only if I enable window list to show windows from all workspaces. So, the bug most probably is in that code, which notifies the window list about windows on different workspaces/viewports or in the panel/window-list handler which handles this notification.