Missing icons on Mac Rated 5 out of 5 stars

This is an amazing add-on that I can't get online without, a true lifesaver and productivity tool. No power browser can live without this.

Unfortunately on Firefox for Mac, the toolbar buttons in split panes do not display even though they take up spaces. What I have to do is to "guess" the location of the back, forward, and reload buttons whenever I need to click on them.

This is extremely annoying, because the buttons are there, just not displaying properly. I thought this is a theme or skin problem, but I've tried the default themes plus whole bunch of other skins, none of them would display the buttons.

This problem is specific to Mac only, hopefully this requires just a simple fix of settings that I haven't been able to find yet. Anyone else having the same problem?