After a recent firefox upgrade, the integration with the unity launcher went pear-shaped. Clicking on the Firefox icon does not move focus to the running firefox, but starts another firefox instance / window. I tried removing it from the launcher and re-adding it but I couldn't re-add it in any way except adding a Firefox shortcut launcher to the desktop and adding that to the launcher, but the same problem persists where clicking on the icon just opens new Firefox windows instead of bringing up the existing window.

I'm running Ubuntu 11.04 64 bit with normal Unity desktop.

Is there a way to reset the configuration of the launcher to work normally with Firefox again?