This makes IME (IM, Input Method) disabled automatically when you focus to the location bar. This will free you from stresses of unexpected handling by IME(IM) when you wish to do direct input.
Sorry, this works only with Firefox 3.6 on Windows or Mac OS X. Firefox 3 on Linux is not supported because of "ime-mode" specification.
If you see any problem, see FAQ at first. If there is no solution, post a report to the issue tracker on the GitHub please.