Why is my trackpad button still clicking but not working?

Hi Guys,

My trackpad button has just stopped working. I can use 'Tap to click' but I can't drag anything to the trash for example.

I followed the guides to remove the battery and restarted the MBP connected to the power cable. This made no difference at all so it isn't the 'swollen battery' issue I've read about.

The battery is now refitted and it is exactly the same. I recently did a routine software update to 10.6.6 but that is all that has changed.

Thanks for any advice!

rich