macbook problem with clicker

I know there were a lot of threads like this back around 2007-2008. My computer is a macbook, I got it Christmas 2008 with 10.5.8, installed 10.6.8 on it. Intel Core 2 Duo, etc.

Ok. I had the problem where the clicker is always stuck: on desktop, it keeps drawing selection rectangles, when I click on something, its hard to deselect and will usually drag it. I tried resetting SMC and other stuff, like:

https://discussions.apple.com/thread/2539560?start=15&tstart=0
"1 shutdown
2 connect power adapter
3 press and hold left shift + control + option, press power button once, wait 5 seconds
4 press and hold command + option + r, press power, hold p until second chime"

I tried resetting the pram using the instruction from apple:

http://support.apple.com/kb/HT1379 didnt work.

I tried going into trackpad, I turned 2 finger off, and that created the opposite problem. Clicker would hardly click anything. I'm messing with it right now. Only zoom and clicking are selected in Trackpad.

I tried using the computer with the battery removed because someone mentioned a swollen battery might be the cause. Nope.

What should I try next?

 

K THANKS FOR THE ALL THE OVERWHELMING RESPONSE GUYS YOU'VE BEEN SO HELPFUL

Anyway I saw the guy at geek squad, he said the most likely problem is hardware and that I might need to replace the part. He himself couldn't do anything about it.

A topcase is kinda expensive I was wondering if there was an alternative.

Is it possible to buy and install just the trackpad specific part?

 

Went to the store, damn thing worked fine when the technician came over and started messing with it. She said if I wanted to I could get the topcase replaced for free since I got in under 4 years ago. I said I would take it home, see if it happens again and if it does take them up on the offer. I kinda want to buy my own topcase so I can keep the original and screw around with it see what the problem is.