I've had this code come up a few times before, and there's nothing wrong with my oil pressure sender. As a matter of fact, the other day I started my car up after being garaged/disconnected for 2 months, and I got a no fuel reading on a full tank.
When I check my DTCs and see this oil pressure switch failure code and nothing else, I'll reset the computer, either that or drive it a bunch. It takes something like 10 starts for it to work it's way out. My gauge still dummies to the middle of Normal, thus why I installed a real gauge.