The tab bar will occasionally 'wiggle' or 'flicker' when the arrow buttons are displayed. It appears that
the arrow buttons rapidly appear and disappear, causing all tabs to resize, causing conkeror to dominate
the CPU. My guess is there is some quirk in the tab bar's css, or a bug in xulrunner. The tab bar hooks
appear to be behaving themselves.

Also, over time tab size will be come disproportionate; i.e. some tabs will be very small while others
will be very large.