Are 2002 Jettas prone to transmission problems?

I bought a 2002 Jetta 5 months ago and ever since it seems like sometimes it clunks into reverse and shifts roughly when going from 1st to 2nd. The car has 153,000 miles on it. Am I taking a big risk by keeping this car? Are these models prone to transmission problems? I have the opportunity sell it in a couple of weeks but I kind of want to wait until the spring when my budget would allow a nicer car. Not sure if I should keep or sell? Any comments? Thanks.