Rated 5 out of 5 stars

When entering Customize Toolbar mode, lots of buttons lost their icons (empty), they are: Forward, Delete, Print, Mark, Stop, File, Archive, Next.
Their icons are properly restored after exiting Customize, but using them blindly while being in this mode is hard.

This review is for a previous version of the add-on (0.4.6).  This user has other reviews of this add-on.

Right, I forgot about customize mode. Should be working fine now.