Trouble with Zoom In/Out keyboard shortcut

In Keyboard Shortcuts, Zoom In and Zoom out are listed (under Universal Access) as option-command-+ and option-command-(minus). To activate those keyboard shortcuts, you need to check the appropriate boxes in Keyboard Shortcuts.

I've set F1 and F2 on my bluetooth keyboard to correspond to those commands.

But the Zoom In/Out option has been turning itself off.
I notice this especially after leaving Front Row.
In fact, almost every time I leave front row, the zoom in/out shortcuts are no longer checked off in Keyboard Shortcuts.

Why is this happening? There's another shortcut for "Turn zoom on or off" which is option-command-8. But whether or not i have that shortcut turned on, the result is exactly the same: when I leave front row, the zoom in/out shortcuts have turned themselves off.

Help?

[Edit: I should add that when I exit Front Row, it's not just the F1 and F2 keys on my keyboard that don't work; the shortcuts themselves (option-command-+/-) don't work anymore. The shortcuts are actually turned off. Why?)]

 

Okay. So. Maybe this isn't a common problem.

If someone with a couple of extra minutes could give me a hand, though...

Experiment to see if anyone else has this problem, or if i'm just lucky:

1. Go to the Keyboard Shortcuts under the Keyboard & Mouse pane in System Preferences. Turn on "Universal Access," including Zoom.
2. Forget about it. Go about your business. Try using FrontRow.
3. Later, return to Keyboard Shortcuts, an see if Universal Access has turned itself off.

Thanks, anyone.