Windows 7: Why do my "pin to Windows Explorer" items disappear after a few weeks?

If I drag a folder to the taskbar, I am given the option of pinning that folder to Windows Explorer (on the taskbar). However, after about a couple of weeks or so, the folders that I've pinned to Windows Explorer no longer appear on the list of pinned items when I right click on the Windows Explorer folder on the taskbar. I then have to re-pin those folders, only to have them disappear from the list after a couple of weeks. Why does this happen? Is there a way to keep those folders pinned permanently?

Did you click on the task bar and select lock?
Lets see if that works.

No I didn't. I'll give it a try to see if it works.

Wish you luck

Well, I tried the lock taskbar thing. But the pinned items disappeared after a few days. I think what I'm referring to is what's known as a "jump list". And apparently for some reason that "jump list" resets itself after a certain amount of time. I need to find a way to prevent the list from resetting itself.

The default # of jump list items is 10. But you can change that in "Customize Start Menu" - via start orb properties.