My trackpad "hotspot" moved

I normally press on the lower left corner of my trackpad to click on a link, open a software program, etc.

All of a sudden, the "hotspot" moved. I now can't open a link or software program unless I press on the trackpad near the center. The problem is, it's impossible to remember the exact location. So I wind up clicking half a dozen times as I move my finger around.

I opened up Trackpad in System Preferences, but I can't find any reference to this particular function. Any suggestions?

Thanks.

P.S. It occurred to me that I may have been doing things wrong from the beginning. What's the standard way to open a hyperlink, file, etc.? I would normally put the cursor on the Finder icon in my status bar, press my trackbar once with one finger in the lower left corner, then put the cursor on a file, and double-click in the same location to open it.