Bug when closing right tabs Rated 5 out of 5 stars
I would post a bug on your bug reporting system, but I just get a 404 not found on that link.Clicking on "Close Right Tabs" does not close the right tabs in the group. Instead, it closes all tabs in the last group. Significant problem there.
Rated 5 out of 5 stars
The problem under FF 19 is that TGM and Tab Mix Plus conflict. I got back to almost exactly my preferred layout by disabling Tab Mix Plus and enabling Tab Utilities in order to get multi-row tabs. Only problem is that Tab Utilities cannot precisely control variable width of tabs, so all my tabs must now have the same width. That is a small price to pay to get back TGM and multi-row tabs.
Rated 4 out of 5 stars
Even if I recreate all my groups using TGM in FF 19, the next time I load FF the groups are gone, even if I load a saved session.
Firefox 19 messes it up Rated 5 out of 5 stars
It appears that Firefox 19 messes up TGM. For example, my groups are now all gone. Instead, FF 19 loads all my tabs in a single group called "Start." Alex, please issue an update to make TGM work with FF 19.