[samclem]

I'm surprised the bleach didn't take care of this. I doubt that the problem is anywhere in the intake system of the machine--there's just a set of solenoid driven valves, and shouldn't be anything where there's open water exposed to the air.

I don't have any direct experience with a problem like this, but here's what I'd try:
-- Let the tub fill entirely with your water/bleach solution, and run the machine. It's possible that the offending water is caught in some sort of seal located high up, and so it will need to get this bleach solution splashed into it. Don't go crazy with the bleach--it's tough on rubber, and the higher concentrations will be even tougher. Maybe go a 2X stronger than your machine recommends for white clothes.

-- Make sure the machine is level. If it isn't then water may be getting stuck int he bottom of the drum between loads. That will cause stinkum. In fact, you might need to cheat a little and angle the machine toward the drain outlet very slightly (watch it closely on the next spin cycle to be sure everything is okay).

-- Leave the lid open between loads. This goes for all washers.

If this doesn't work--buy a Staber!