Microsoft Excel Toolbars Reappear After Deletion

I have a problem where I have a number of user defined toolbars that I delete using these steps:

1. Tools->Customize->Toolbars
2. Highlight toolbar name
3. Click Delete button
4. Toolbar is removed from list and screen.

However, when I exit and reenter Excel the toolbars magically reappear!

What’s going on?