Manual transmission problem

I own a 1990 Toyota Corolla station wagon with 138,000 miles and a 5 speed tranny. Recently a problem with shifting has occurred. With the car running, you can't move the shifter to other gears from neutral. It almost feels like the shifter is stuck. There is good clutch pressure though. Could the clutch be going or is there a problem with the shifter linkage? We had the hydralic line bleed and there was no air in the line. You can shift it into reverse but it is very hard to get it back into neutral. Then if you let the car sit a day or two, the shifter works fine for awhile. What could it be? Any suggestions