My 2000 Forester Tranny is having problems engaging into drive from either park or reverse upon take off. I need to rev the engine to about 2k rpm b/4 the transmission will shift into first gear after shifting to drive. Occasionally this will happen within the first few stop and starts after initial take off. It has never happened after driving for a significant distance i.e. 10 miles or more. Once it is engaged it drives without issues. I've owned the car for about a year, and this seems to be recurring more often. Fluid is full. Thoughts?