What steps will reproduce the problem? 1. Open pencil

What is the expected output? What do you see instead? Until you restart firefox, every 10 seconds, all of firefox (by that I mean the gui thread), including pencil, will freeze for 2 seconds.

What version of the product are you using? On what operating system? version 1.2 build 3003101501 Ubuntu 10.04 Lucid LTS

Please provide any additional information below.