I think I can answer this as I am in the middle of this going on.
I had my computer flashed a month ago (after owning it for 2 years). Runs way better and allows me to use the Supoerchips properly.
It started flashing the TMPS when I would be driving it on pavement at constant speed for more than 15 mins or so, would flash 30 times.
I asked the dealer about it and they said to check the tire pressure...duh...anyway, I have 4 larger tires that I run 38#'s in and the factory spare that I have 32#'s in. I guess now that the computer is running correctly, it is registering the problem. Seems the sensors go off if there is more than 2-3#'s difference...haven't bought a larger tire yet nor have I had a chance to air down my main 4 close to the spare but it makes sense..