Have the reseller remove the mac and put it back which will clear any stored infor on voodo site and then try again
It sounds like to me that the reseller had activated your account as a Mac based account and you need a username and password setup which can only be done if you get a new sub because you cannot go from a Mac based to a login based but you can go from a login based to a Mac based
You have to add the MAC address on STBemu that you provided to your reseller. If you did that, it shouldn't ask for ID password.