Well, I get email notifications for the comments here :)
Unfortunately, I cannot say much without having a way to reproduce it. If you can find a scenario where it stops working, please let me know.
Also, disable_topmost=2 does two things: makes the taskbar non-topmost, and allows windows to be maximized beyond the taskbar. Which of these two features stop working?

Hi,
No, I have no idea as of why this happens. Are you using any extra customizing tools, such as Classic Shell?

It's not available in v4.5.9.2. I've just released v4.5.9.3, please try it.

A duplicate of http://tweaker.userecho.com/topic/534868-latest-update-shows-7-taskbar-tweaker-could-not-load-library-206/

I don't have update checking on

That's unexpected. So you disabled update checking, and you still experience crashes? Could you post a crash report?

Looks like a duplicate of http://tweaker.userecho.com/topic/534868-latest-update-shows-7-taskbar-tweaker-could-not-load-library-206/
Please try the beta version, which should fix the issue.

Implemented in 7+ Taskbar Tweaker v4.5.5.5 beta.

Fixed in v4.5.5.

I believe that it's an issue with the MinHook library, which was fixed in the beta version (v4.5.5.2). Please try it, and let me know if you encounter similar errors with it.