touchpad 'sticks' as if depressed, but isn't

I have a mid-2009 13" MBP, and am experiencing an issue with the touchpad.

Although it does not appear to be physically sticking (i.e. it rebounds/clicks upon release), when I move the mouse, it attempts to highlight everything as if it is depressed. Or, let's say I clicked an application in the dock... now the alias tries to drag off the dock when I move the pointer. I have to tap it hard for this to release, and then it tends to start again after a few more mousing moves.

I experienced this maybe 6 months ago, but the issue went away after I tapped it hard a few times.

Is anyone familiar with this issue?

 

Thanks for your response.

I had read a few threads, where the trackpad was physically not returning to the original position due to the battery -- but didn't see it reported when it was physically working as expected.

To clarify, in your case the track pad seemed to click (down and up) fine, but the cursor behaved as if the pad had still been depressed?

 

Thanks for the suggestions.