Comment 9 for bug 548652

I tried adding gtk-auto-mnemonics = 0 to a new file balled .gtkrc-2.0 in my home directory and logged out and back in but that did not fix it (thought it was worth a try based on some of the things I'd read on the net it sounded like it would honor the setting).

Changing from Radiance to Human fixes the issue. Also you can add the standard Menu Bar to the Panel and that one does work with the new themes. Normally I keep that one off since the words "Applications, Places, System" takes up too much horizontal space and I use the one called Main Menu which just shows the Ubuntu icon.