And do you have an extension with that name? Do you see the same problem in safe-mode / with a new profile? http://support.mozilla.com/en-US/kb/Safe+Mode http://support.mozilla.com/en-US/kb/Basic+Troubleshooting#Make_a_new_profile
I have the 4chan Firefox extension, so that would actually make a lot of sense. No I haven't seen it running in safe mode or a new profile.
Issue appears to have been caused by an extension. Resolving as invalid, please notify the extension author - if the addon was downloaded through addons.mozilla.org there is the option to leave feedback there.