How to fix windows seven jump list left click disabling problem?

Currently the jump lists in the taskbar have stopped working correctly on a clean install of Windows 7 32bit RC ver. 7100. That came about without installing anything new. I have run with it for the last 4 or 5 weeks but the usefulness of the lists are being lost. The same goes for the jump lists contained in the start menu.
If I open a jump list for a pined program such as Windows Media Player or the new Zune 4.0 software, any items in the list will do nothing. The same goes for Google Chrome which now supports jump lists. What does still work is Windows Explorer and some of Internet Explorer jump list links. All others fail to do anything when clicked. I have tried to disable and enable jump lists by turning off and on the recently opened docs and programs in the task bar properties.
I have done a system file check. I am not running anything like CCleaner or have WinRar installed which I know can cause an issue with some people. I have tried this with different user. I have tried a system restore to a time when it did work. But I got no good result.
Can anyone help me to fix this?
Thank you
