X230T issue with touch screen?

Basically, I've had my X230T for 4 days now, and I've been starting to have a problem with the touch screen. Basically, I've been using the touch screen for everything I used to use a mouse for, and I've been using it a lot in tablet mode. The problem started about 2 days ago.
What happens is that somehow, when I touch the screen, it gets the vertical (I'm looking at this from the notebook mode perspective) location correctly, but something on the horizontal location messes up. It thinks I'm either:
1. Touching where I'm actually touching
2. Touching on a point along a vertical line that is about 2 inches off the left edge of the screen
3. Touching both above points at the same time, often causing SimpleTap to be opened.
The problem is only with finger touch, and when I try the pen, it works just fine. In fact, I've had no problems with the pen until now. I'll usually be using it for a while, and all of the sudden the problem comes on. In the last 2 days, I would just play with it (touch it a couple of places), sometimes get out the pen, and usually the problem would go away again, and I could work on. But today, more specifically this evening, it has gotten a lot worse. I have a hard time getting out of the problem, and the problem only leaves for a couple of seconds, until it comes back.
At first, I thought it was a driver problem, but now I'm wondering about that. The vertical line that I mentioned doesn't physically change with the screen orientation - in the sense that when I'm in portrait orientation, it's a horizontal line. It has been very hot in my area recently (reaching 100F), and the problem does seem to be better or worse depending on the temperature - the hotter it is, the more of a problem it seems to be. But a computer (especially a thinkpad) should be able to take temperatures like this, right? I don't mind the fan going stronger because of it (it's still not sweating as much as I am), but the touch screen not working? I mean, there are places where it gets even hotter! And the other thing - today wasn't the hottest day (at least I don't think so, the differences between the days aren't too big), but today I've had the most problems, although they were mostly during the hot part of the day. The only other thing I can think about is the screen protector I put on it. But then, I've had at least a day of problem-free operation with this with the screen protector.
Has anyone else had this problem? Is it maybe just a driver issue? I will be contacting Lenovo in the next while if it's a warranty issue, but I hope that I don't need to do that as it might be a bit of a problem in terms of the country, and that I don't want to be without this machine...