Comment 22 for bug 154504

Does this need any more info or confirmation?

It happens to me too. I notice the icons are smaller than they were in Feisty.

It is as though the button sizing function thinks there is only half the height in the (vertical) panel than there actually is. Each time a new window is opened, the icons shrink yet more until the 8th is opened at which point gnome-panel starts eating cpu usage and ram. (xorg cpu usage also up a bit too).

Nvidia driver and desktop effects enabled.