Comment 16 for bug 551328

i also had this problem with my initial account on a fresh install of 10.04 64 bit. installed adblock+, greasemonkey, xmarks, flash, then later installed icedtea java. applets work fine, but cpu usage goes to 100% and doesn't cease until firefox is closed. under a new profile (moved .mozilla) plug-in works as expected.

unless it is caused by one of the addons i have, the only other thing i can think of is that i installed icedtea plugin and then used it without restarting firefox. will try to install addons again to see if problem comes back.