Comment 9 for bug 293637

This bug appears in GNOME for me as well! No traces of XFCE here on a fully updated Jaunty system.

When there is a Synaptic progressbar on screen (downloading packages), top reports Xorg CPU usage is as high as 50%.

The CPU usage drops to nearly 30%, if I switch themes on the fly to Simple, Industrial, etc. It does not drop that much with Clearlooks and Crux.

As soon as Synaptic finishes its downloads, the CPU usage goes to 5-7%, but if I launch thewidgetfactory (Human theme again), it raises to ~20%.

The widget factory does not show any increases with Raleigh, Redmond, Clearlooks and other themes with static progressbars.

I also suggest it may relate to the Murrine engine, not the Human theme after all.