--------------------------------------------------------------------------
"living with it as long as it doesnt get worse" has a downfall to it, while its not getting worse is it causing any damage that when it causes it to "gets worse" is going to be costly ?... as its not an isolated problem as more then one of you has got it, it would be worth investing as much time as needed as "prevention is better then cure"...then when i win the lottery and have one of these fine machines i will know what to do when i hear it..
I was thinking that, especially if there IS water in there. Seals have been known to pack up. I suppose what would happen next would probably depend on whether there was a warranty still available - if so, I'd probably be in touch with the dealer pretty smartly.
Failing that, I'd have to take a careful look, but your options might preclude the latter - in which case, hopefully someone on here might have more information. I'm thinking in terms of the fact that it ought to be possible to flush it out with suitable solvent without dismantling and then re-lubricate, either with oil, melted grease (difficult), or grease in a volatile solvent which would evaporate after a short while (and preferably before the unit was next used). If a seal has gone, though, the problem would obviously recur unless you avoided bad weather riding.
I'm sure that such an item which was noisy in the wrong way or otherwise malfunctioned would be on borrowed time without attention, and I understand these multi-speed hub gears cost an arm and a leg to replace. I also expect that even if it could be dismantled and successfully reassembled, any worn or damaged parts would mean replacement of the whole thing rather than repair, as components would probably be unavailable.
Rog.