Comment 16 for bug 111299

This
http://primates.ximian.com/~federico/news-2007-09.html#firefox-memory-1
http://primates.ximian.com/~federico/news-2007-09.html#firefox-memory-2
mentioned patch set as a side effect corrects this behaviour. I had a discussion with the author and it should be guaranteed at last to free the pixmap in all scenarios. I heard also that the patches have got really good chances of making it upstream for the next Firefox release.