That “fix” I blogged about yesterday for the Shmoo Group's Firefox exploit gets unfixed when you close and re-open your browser.
Information on a more permanent but alas more complicated fix can be found at tech.life.blogged.
UPDATE: This item was originally posted at 7:22am this morning. Some time between then and now, Firefox posted an update which fixes the problem. Quick work! [For the windows users who wrote me with their worries, the file you want is: firefox-1.0.en-US.win32.installer.exe . Just download it, then run it.]