Rated 5 out of 5 stars

Please add a code to support MacOSX, it's easy: you just add custom scrollbars as it's done in iPox, Whitehart, Silvermel, Stratini, Rein, or in Smoke or FennecFox (not from default theme).

This review is for a previous version of the add-on (3.03). 

MacOSX (and Linux) support

Thanks for the tip. I was already looking into fixing this issue. It is just that I have no way to test any changes to see if they work properly. Have a look at my web page to see a transcript of what happened when I tried to get help with this the first time:
I may have found someone who can help with testing on Mac OSX and Linux.
I was recently looking at a theme not mentioned in your list that seems to have a simple solution. I will have a look at the ones you mentioned if I have difficulty with the present one.