MacBook Pro :: Trackpad Stutters Or Stops Working Temporarily

I noticed my trackpad started acting funky last night. It won't happen right away when I turn my MBP on, but usually after some time (depends). First thing that happens: it responds slowly; it will move the pointer less than it would normally and it will judder along. Pressing harder doesn't help and sometimes two-finger scrolling won't work one way, or sometimes using my other finger will work better. After some more time, it will stop responding entirely or get unusably slow. I noticed restarting fixes it (temporarily; once again, it depends). Just before posting this, it happened until it didn't want to work at all, and I let it sit for a few minutes, came back, and it worked fine. Ten or so minutes later, its still working (no restart). It's troubling and I'll probably take it to an Apple Store to have it checked out, but I won't have time to do that for some time, so I'd like to see if this is possibly something well-known or fixable.

I thought it might be dirty, but I cleaned it, well, a few times, and still nothing. My hands are clean, too. I thought it might be something I "spilled" onto my keyboard a few days earlier; it wasn't anything watery, it was a rather thick consistency. I hope that isn't it, as I cleaned it quick and well, and it wasn't on the trackpad, and the keyboard works perfectly. The only thing I was doing when it first happened was video chatting via MSN (MSN gets my Mac hot, and I was worried it was the heat that did something, but IDK for sure). I only started using MSN about a week ago, and it gets my Mac really heated each time I use it. I did some searching on Google about this, but nothing quite like my situation. I haven't looked at everything, but, nothing yet.