Built-in trackpad suddenly bugged!

I was using muy computer this morning, but suddenly when I opened Safari and started browsing something, something went wrong. I can move the mouse cursor, do all movements with four fingers up, down, left and right, it clicks but it won't respond my clicking/tapping commands.

Also when I scroll the cursor over the dock icons, they don't react nor highlight, as nothing was going on. So, this is it, it looks like a bug, it happened all of a sudden, I can move the cursor but it won't be recognized, I cannot click anything also.

Already tried to reset the NVRAM by clicking command+option+p+r during startup as well as shift+control+option+power button for 10 seconds before startup, nothing happens!

Did anyboby ever had this issue?

P.s.: I read some previous questions about a bulging battery pressing the trackpad, but I don't think it is my problem, because, as I said, it looks a software problem, not hardware: I can click, I can tap, but computer won't respond, even though I can move the cursor and do other finger commands on Lion.

Please help!