i don't know where this information originated, as my mom claimed to have found it somewhere several years ago, but she seamed very convinced while dissuading a friend of mine (a hamster owner) not to get a chin, because of her hamsters. ordinarily, she is prone to getting information from good sources, so i will pass it along, anyone with more experienced knolledge regarding chins and hamsters in the same household, please correct me if it is untrue.
my mom told me that chins and hamsters had some sort of territorial aggression, where one (i do not remember which) would basically attempt to find and kill the other after encountering the mere scent of it. causing stress to both, and possible harm if they did manage to somehow come into contact. i have never herd it verified or tested... Also, she said that the fumes put off from the mixture of ammonia and cedar are toxic to chins, this i would be inclined to believe, since that one of the reasons you don't use cedar with chins. In any event, i would keep their respective dwellings a distance apart, or even in separate rooms, if only to prevent the fumes from reaching the chin.
also, keep in mind, i have never owned a hamster, and only have heard that cedar is one of the most popular beddings.
so basically, take this with a grain of salt, cause i don't personally have the chin+hamster experience to back it up with