Please provide a crash report.

Closing as a duplicate of:
http://tweaker.userecho.com/topic/142187-it-would-be-really-great-to-have-the-possibility-to-always-expand-groups-with-more-than-1-item-and/

Thank you for the positive feedback and for the donation!

That's already possible with the "multipage_wheel_scroll" advanced option. See the help file for more details.

The improved version is not a standalone program, it's a patch. I thought there's no reason to complicate things just to replace a single icon.

Yes, it should be located in the same folder as the tweaker's executable file, and should have the same name.
Also, thank you for the donation!

Done in v4.5.6.2 beta: if the file "7+ Taskbar Tweaker.ico" exists, it's used as a tray icon instead of the original one.

Why do you think that 7TT causes the issue?
Did you try to use your PC with the tweaker turned off? Does it fix the issue?
In general, from your description it sounds like Dexpot is the app to blame here, as it handles the virtual desktop switching.

That's a good idea, thanks. I'll look at it.