I have the same hamster and it just died too. It was kind of exactly the same thing, and my hamster looked just like yours did. It was only about 4 months old and I just found it in its little lookout dead... It had been smelling funny for a while and I was really bothered by it. I think it might have been wet tail with my hamster too because its back was wet when I found it dead too. May little Bamboo and my dear Bip rest in peace...