Silvermel looks mostly correct here on TB 31. Did you just go ahead an enable it, despite the "incompatibility"?

Thank you. Yes, I used an add-on to disable compatibility checking but it didn't look like your image. in my current configuration, I have a Title Bar, Menu Bar and then all the icons you have below tabs in your image in the same bar as the tabs right above the Quick Filter Bar. When I updated, I had icons hiding what appeared to be Chrome shaped tabs. I admit I'm nervous about updating again in case I develop the issue others report with updates happening even when turned off; I admit that I no longer trust Mozilla to respect my choices in customisation.

sounds to me like you have an add on... perhaps rise of the tools which is messing up.

Sorry, family issues have taken over my time, so a very delayed response. I don't have Rise of the Tools. Hoping you might have some other ideas - can't believe I'm the only one who wants square tabs below menu bar, even if I have to let go of Silvermel which is no longer being developed. Any ideas of what to do next will be greatly appreciated. Meanwhile TB24.6.0 with Silvermel still working fine.

" can't believe I'm the only one who wants square tabs below menu bar" There are not many of you. Most these days want no menu and they certainly to not want a space wasting windows border (Their words not mine)

When the tabs on top first appears I to was reluctant, even filing enhancement bugs for it. Ultimately it was a storm in a tea cup I got used to it and the quirks of having a toolbar that randomly appeared and disappeared depending on the tab context.

However much as we might not like it. Windows XP is dead and so is the classic windows style. You have made the transition to Windows 7. Now make the transition to round corners on tabs

This attitude is a big part of the reason Mozilla is slowly fading away. You forget that we all became fans because FF and TB could be customised to suit our individual quirks, because we wanted things how we found it useful to have things that suited us.

edit: removed personally insulting content, this won't be tolerated in our forum. refer to the Mozilla Support rules and guidelines (philipp)

If you don't like the direction that new versions of Thunderbird are going in, you can get old versions here:

https://ftp.mozilla.org/pub/mozilla.org/thunderbird/releases/

No need to use a restore point.