Do motors just "wear out" after a while?

Yesterday my 3.8 would get locked up like there's a dead spot on the commutor or something.. Once it was moving, it was fine, but once in a while you'd stop and it'd just refuse to move. all the other motors work fine. I tried it with different gear sets and it's not gear binding. pick it up and hold forward and nothing, but if you'd rotate the wheels the slightest bit manually, or give the car a nudge, it's running like gangbusters again. This is a BitChar-G Motors 3.8. It ran fine for a while, till yesterday. Is this just normal?

By the way, I bought the motor about 11 months ago, but packed up the whole Microsizers and Zip Zap thing shortly after that, this motor probably has less than 50 runs on it, as I use it mostly for drag races and straightline timed runs. When I'm not drag racing, I'm running around on my desk at work, using the 1.6 motor with 12:1 Axles. Occasionally I'll drop my ZipZaps "Nos" motor in and go to the server room because it has a nice flat floor. The car flips over when turning with anything faster than the NOS (equivalent to something like a 2.5 motor I believe)

The only other thing I can think of is the fact that the last 5 or 6 runs I made with it were in my new Microsizers Pro, and since almost all the runs I made with it in the pro were drag races across a gym floor (probably 100 feet, I know, should have been 20), I was pretty much on turbo mode the whole time. Is it possible that the M/S Pro killed the motor?