I'd also check and re-torque the thermostat housing bolts and double check any hose connections. Be careful not to crack the housing by over tightening.
Tucker: I would first let a trusty repair shop have your cooling sys. pressure tested. This is a very cheap and easy way to pin point a leak. Most shops can do this for you in a short time. I would also check into replacing the water pump. It sounds like yours is starting to go bad. Often...