Recently opened programs in vista

I cleared the list of recently opened programs (under the pinned programs) in the start menu of Vista. I believe the option for this in the cleaner settings is "User Assist History".

The issue I am having is that this area of the start menu no longer contains any recently used programs even after I have launched many programs using the start menu after the cleaning procedure. The space for the programs is there, but I am unable to fill it with recently opened programs.

Restarting after the cleaning procedure seems to fix this issue.