Stall in rinse cycle?

My front load washer recently began to stall during the rinse cycle. I must manually advance it two or three times to complete the cycle. This problem occurs in all the different cycles ie. delicate, regular, permanent press.
The pump seems to be working fine. I replaced the timer but the problem remains.
Any ideas what to check next or maybe a troubleshooting flow chart?

GE FrontLoad Washer WSXH208A1WW