Tranny problem Belarus 825 MFWD?

My '93 Belarus 825 mfwd, after sitting, will not move when put into gear. I have to shift it through the gears a few times and then all at once, it will move and be strong. There is no slipping, so I know it does not need a clutch. I have not been able to find any forums on the net of similar problems like this. Anybody know what might be going on here?