Ihre Kommentare

Yes, I'm familiar with the issue (which is different from the one presented in the original suggestion).
I'll see what I can do about it.

I believe the issue has nothing to do with the tweaker.

If you think otherwise, e.g. the issue occurs for you only when the tweaker is running, please let me know.

Closing due to lack of input.
Please reply if you have more information about the issue.
Taskbar Inspector always opens near your cursor, I think that's most convenient.
Why would you want TI to appear at the top when you click at the bottom?
7TT doesn't make permanent changes to the system, so if you disabled autorun, restarted, and the issue still wasn't solved, it means 7TT is not guilty here.
Uninstalling it won't change much.

I'm pretty sure it's not 7TT's fault, but the best way to make sure is to close the tweaker and restart Excel.

That said, Excel was reported to have some other issues with regard to the taskbar, e.g.:

http://rammichael.com/7-taskbar-tweaker/comment-page-11#comment-2312