I just switched from an NVIDIA to an ATI graphics card and changed the graphics drivers on my Gentoo distro accordingly. Surprisingly, gnome-shell worked without any noticeable problems (I know there have been many reports of problems with ATI drivers.) However, I also use the fallback mode, mostly in an NX session, and it just looks ridiculous.
As you can see, there are three copies of the menu bar, three copies of the date and time, three copies of the top right menu, three copies of all my open windows and tabs, three copies of the workspace switcher...and the top and bottom bars are three times higher than usual. This only happened after the switch from nvidia to ati drivers, but I have no idea why it is happening.
I'm on gnome 3.4.x - clearly this is a bug, but given that the fix for it won't be quick, I'm looking for a workaround. Does anyone have any suggestions for tracking down what is causing this so that I can find a way to temporarily fix it? As a hint, while I was upgrading the drivers on my system, there were two copies of everything for a short while before it became three copies.
I observed the following in dconf-editor; whatever caused it could be part of the problem: