Windows 7 Pin to Explorer no longer functions

For some several months now I have been happily using the "Pin to Explorer" function as a means of quickly accessing several folders, last night Windows installed a critical update of some sort and on rebooting this morning, right clicking the explorer folder on the task bar showed all my pinned folders gone, I dragged a folder to the task bar and got the "Pin to Windows Explorer" option which I selected, but to no avail, nothing is pinned any longer. I do have "store recently opened programs" checked as well as the second option "store and display recently opened... etc"
this seems not to have any effect.

I tried a system restore prior to the update, no change.

any suggestions as to how to restore this function?