I just received a report from another user who experiences the exact same issue. It seems to occur when plug-ins are being used by a webpage. If there is any more information I can provide to help solve this, let me know!
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1010208 Title: Firefox 13.0 on Lucid hangs very often, sometimes a JavaScript hang dialog is displayed To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/firefox/+bug/1010208/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs