Yeah I went through the whole usual processes. Cleared cache and deleted .mozilla. Then systematically uninstalled programmes that I had added or updated within the past week. In between each I killed Browserd and rebooted. Still kept coming back till I got to FCAM.
Like I said a very unlikely source of the problem and Im still a bit stumpt as to what happened.
My next step is to reinstall FCAM and see if problem comes back.