Comment 5 for bug 537050

For me this is reproducible by selecting any of the Websites in the left sidebar, like "Legal Torrents" as pointed out before.

Also, this might be the reason why the canvas is not drawn anymore when going to another Website (where the error happens again - looking at the console) and back to a previously selected website.

willkg on #miro-hackers said it's probably related to lucid / xulrunner.