GE top load still leaking after new tub seal

Our GE top loader sprung a leak at the shaft. I replaced the tub seal (the old one was much more the consistency of a hockey puck than rubber so my confidence level was high), but it is still leaking. I pulled it back apart, and the seal had come up out of its seat in the outer tub. I re-seated the seal, but it still leaks from the bottom. I disassembled things again, and the seal had stayed in place. Any ideas before I give in and call a repairman? Would this be a sign that the shaft itself coming into the machine is damaged?