Excel formula flicker / erase formula / won't close

[robotman]

I'm having a really weird problem with Excel. I'm hoping someone has
seen this before. Here are some of the problems. It appears like
Excel is stuck in some loop. Maybe a bad system file?

1. Excel CPU usage is around 75% even when I'm not doing anything in
Excel.

2. When I try to edit the formula on the formula bar, Excel just types
garbage and erases the formula.

3. The formula flickers like it's being refreshed over and over.

4. When I drag and drop, the contents vanish.

5. Excel won't close even if there are no workbooks loaded.

I've tried uninstalling / reinstalling Excel and the problem persists.
I don't see any weird problems in any other program. There haven't
been any system changes that I know of.

Has anyone else seen this problem? Any ideas?!!

Help!

 

[robotman]

I held down SHIFT while starting Excel and Excel behaves normally.

Now every time I start Excel (without holding down anything) it said
"Code was interrupted" and gives me the option to Continue or End (no
Debug option).

Have some trial and error, I have narrowed down the problem to be with
the Analysis Tool Pack - VBA add-in. If I remove this, Excel loads
correctly. If I include it, it now gets the error (but still behaves
correctly afterwards).

Anyone know how to repair this add-in? Any insight into what happened
to the add-in to make Excel act so funny?!!

Thanks.