Missing Compatibility Tab

I've noticed that on my copy of Windows Vista I am missing my
Compatibility Tab in my Properties window. It shows as follows:

General Shortcut Security Details Previous Versions

Searching Google has proved mostly useless, though I did find a forum
post on another Windows website but no solution was determined there.
At least I know that I may not be the only one to have had this problem.

I did find the page on using application shortcuts by creating new
strings in regedit instead of an actual tab. I think that should work
just as well, though I'd like to know if there is a known solution or
patch for this problem.

Any thoughts?