Bicycle Mechanics - Shimano Nexus Inter-8 Help?

I got a flat on my Jamis Commuter 3.0 a couple of weeks so I had to remove the rear wheel for the first time. It has a Shimano Nexus Inter-8 on it which I had no experience with. After repairing the flat, I got it all back together and it's shifting and riding fine but there's one little problem. The cassette joint bracket is not staying in place. I line it up parallel to the chainstay then snug up the cap nut but it creeps upward after riding it a bit.

I suspect that I either don't have the non-turn washer lined up right or maybe the cassette joint fixing ring is not locked properly. Can anyone shed some light on this? Here's a link to the service pdf (http://techdocs.shimano.com/media/techdocs/content/cycle/SI/SI_36T0A-001/36T0A-001_SG-8C22-EN_v1_m56577569830612442.pdf) in case that helps.

Make sure you have the right non-turn washer on each side, as they are side-specific. Are the red marks aligned on the cassette joint cap?

the red marks are aligned. i think the problem is with the stock non-turn washers, they're identical for starters and the tabs on them do not extend all the way through the frame. shouldn't they be engaging something on the hub?

I can't find a good detail shot of the Jamis dropouts. So I'm just guessing here. On mine (non turn washers, yellow-right,brown-left) the cassette joint bracket doesn't line up parallel to the chain stay. I check another's with vertical dropouts (blue-right,green-left) and that cassette joint bracket points up maybe about 20 degrees.

I slightly remember when washing my bike a year or so ago that bracket disconnected when I was wiping it with a cloth. I can't remember which, but one direction loosens it and the other secures it in place. I wonder if you try to align it parallel to the chain stay, that loosens the whole bracket. But I can't tell for sure because the alignment is going to be a little different for each type of drop out and I can't figure out what the Jamis has.

the dropouts are horizontal, similar to track ends. my suspicion is the jamis stock non-turns are the problem. they're not shimano parts and actually i don't think they're non-turn. the hole in the washer is perfectly round and therefore not keyed to the axle shaft so how could they be non-turn? i ordered the proper shimano parts from harris cyclery so hopefully they'll solve the problem. thanks for the suggestions.

Keep us updated as to the results.

the shimano parts did the trick although they position the cassette joint bracket behind the chainstay making it a little hard to get to. no big deal but worth mentioning. the only other anomaly is the built-in chain tensioners are too short now. the stock jamis washers were a bit longer than the shimano ones. i assume i could remove a chain link, maybe, and it would solve the problem but i don't think it's a concern. i hope this makes sense, i can take pics if it would help.