Windows 7 - Pinned folder & recently used files disappears after some time

Hi,

I pinned one folder from the "Documents folder" to the taskbar. The Windows Explorer icon is pinned to the desktop, so the folder appears as "Pinned" when I right click it. After some time however, that folder is gone and I have to "re-pin" it. I am not sure why this happens.

Second problem. I use VLC player. All files open in it and its pinned on the taskbar. When I right-click it, I could not find my recently played files. This is annoying since I need to open my music folder and find playlist/files and open it again. Weirdly when it is not pinned and appears in the start menu (most used programs), I can see the files. The moment I pin it to the taskbar, the program is missing from there, and so is the list. I did not get this problem when I first installed windows.

I am using Avast free. I do use Advance System Care Free & Spybot S&D from time to time. I am not sure if this is the problem.