Let me throw something else into the mix....
A while back I refilled a LP tank for my grill at the local LP company (refilled by weight, not a tank swap). When I hooked it back up, not only did the regulator make a noise, but it frosted over and the gas stopped flowing. Apparently it was slightly overfilled and liquid LP instead of the gas form was actually getting into the regulator via the hose. As it flashed to a gas, it froze the regulator. I ended up having to heat it with a blow dryer while keeping a burner lit until I used enough LP to get it to a normal level. After the fact, I remembered there is a bleed valve on the tank on the back of the turn knob where you turn the LP on/off at the tank.
If your regulator is very cold or even frosty looking, try bleeding off some LP at the valve.