I'm assuming that both your summer and winter wheels have the sensors in them. Personally, I don't give a ratz azz about the TPMS system and I'd ignore it. But you should be able to have the offending sensor identified with the sensor training tool.
07 GT Prem: Alloy, MT, 3.55's, Steeda CAI w/Brenspeed tunes, FRPP Stingers, 275/40/18 Goodyear Eagle F1 A/S on SVT Cobras (OE GT500's), 14" shorty, Wheelskin side scoops & qtr window louvers, A-H rear window louvers, SHR honeycomb blackout panel, Sequentials, Hella Optilux Extreme XY fogs, Silverstars
06 V6: Legend Lime, Pony Package, 14" shorty, Sequentials, Hella Optilux Extreme XY fogs, Silverstars