I was having this problem, and found a locked thread on here (due to age). However, I believe I have new information that sheds more light on the problem. (Recap: clicking on one cell in Excel 2007 selects the cell you want, as well as three or so cells below the cell you want.) I am convinced it is a scroll wheel positioning issue, as a previous poster recognized. I am using a Logitech Revolution, with the free-spinning scroll wheel, and noticed that when i switched it back to standard scroll mode and move the scroll wheel a click or two the problem goes away. Cmon Microsoft, admit the problem and patch it!

Another solution that I've come across is that by zooming in slightly, the problem disappears. Not sure ifthat's a permanent solution. I do have a logitech wireless mouse too though. Hmm....