Vista (sp1) Start Menu No Longer Lists Recent Programs

I have a recent problem with Vista (SP1) start menu.

If I <right-click> on the task bar and click on "Properties," and select the "Start Menu" tab, the "Store and display a list of recently opened programs" box is unchecked. If I check it, click OK and Apply, the setting doesn't "stick". I return to the Start menu tab and the box is unchecked.

If I click on "Customize" on the "Start Menu" tab, the "Start menu size" control is greyed out.

Now, if this gives you a hint of where to look for a solution:

Just before this Start menu madness started, I went to Control Panel > Programs and Features > "Turn Windows features on or off" and added a check-mark in front of Games, which had not been previously installed.

After that, I went to "Customize" on the "Start Menu" tab to select "display as a link" for Games.

Poof! My list of recently opened programs disappeared, and from that point on, I've been unable to re-enable it.

Any solutions, ideas, hints on how to proceed to re-enable the list of recently opened programs on the Start menu?