> After skimming through it once more, can you confirm that it originates from 
> the window updating its _NET_STARTUP_ID property? I think it is possible that 
> KDE apps update this property (to the same value) upon every window map. 

> However, while not needed and not exactly nice, if this is the cause, the 
> problem is technically still in Metacity - the startup ID by the time of the 
> desktop switch should be already obsolete (startup sequence ended), so 

> Metacity should not react to it at all.

This serves me right for not checking the mailing list before starting
work tonight: I spent about an hour combing through the code before I
came to the same conclusion:


http://bugzilla.gnome.org/show_bug.cgi?id=400167#c19

I think you're right and the problem's at our end, though perhaps someone
should look into why the KDE apps are updating this property anyway, for

efficiency's sake. I'll work on fixing Metacity to ignore it.

Thanks for your help!

Thomas