01 Jetta GL MAF problem

I have a 2001 Jetta GL 2.0 with about 85000 miles on it. It presents code P0101. Before I spend money on a new MAF I thought I'd ask if anyone has come across this before and ask if there is anything to look for besides the MAF. I checked all the apparent vacuum lines and found no problems. I also thought it might have a stuck cold start valve but I haven’t researched that yet. The engine intermittently runs rough at idle. It usually occurs when the engine is not cold, but has not reached normal operating temperatures. Thanks folks.