Capable to make Thunderbird better Rated 5 out of 5 stars
With this theme thunderbird looks much better and gets a better usability.
But there is an incompatibility with "Hide C. Titlebar Plus Lite" - together wit this add-on no more windows controls (close, maximize or restore, minimize) are seen.
5 stars in spite of this incompatibility but sorry to say, but as long as this incompatibility exists, "Hide C...." is more important for me - I hate this useless bulky caption titlebar bar ...
I know that it doesn't help you, but I'd assume that the incompatibility comes from both Ignore Aero and the add-on you mentioned messing with the main window. Mozilla doesn't allow themes to style the title bar, so Ignore Aero has to force some values there.
Note that it is probably not possible to fix the issue without breaking the style of this theme for all other users, so I won't do anything about it for now. You could, however, probably fix the issue by yourself through an userChrome.css sheet. I don't have the time to create you one, though.
And a general sidenote: reviews are not for bug reports, use the support-eMail-Address for that. Thanks!