I have a new computer and just reinstalled Office 2003. I usually have
several Excel documents open at once, and before I would simply hit alt+tab
to scroll between the documents as well as any other open applications. Now
that's not working between Excel files.

Here's the scenario. I open two Excel files. One of the files has the
focus. Then, when I try to alt+tab to the other file, when I select the file
in the box that pops up when I hit alt+tab the focus does not leave the first
file and the "File" menu item is highlighted.

Maddening! I have "windows in taskbar" checked and for the life of me I
can't figure out why it worked one way on the old computer and why it's now
doing this on the new computer!