I really liked that one, but... Rated 1 out of 5 stars

...to me, it seems like this add-on is simply dead and gone. The last version if Firefox where MRTT worked without problems was FF 3.6 or 3.7, this Add-On hasn't been updated for more than a year now.
Looks like this add-on is now abandoned for good, because there's not even any update from mrtech about the status or what's going on. A real pity.