Originally Posted by Aggrajag
Scratch that suggestion!
Prompted by the comments showing that it actually DOES do what I suggested I've realised that another tray item (TaskBar Shuffle) is actually stopping it working. When I close TaskBar Shuffle the click does indeed work.
Mighty annoying as I quite like TaskBar Shuffle - it lets me drag programs around in the task bar plus also allows me to middle-click to close programs.
Ya just gotta love those program interactions
Glad you figured it out (And reported back what you found to save others time in the future).