see
http://wiki.winamp.com/wiki/SHOUTcast_YP_Nak_Errors for the 480 error.
until that is resolved, no clients will be able to connect to the DNAS as it's leaving the DNAS in an invalid state.
and as you appear to have created the authhash, make sure that
http://forums.winamp.com/showthread....39588#remember is followed (so you don't have to potentially keep creating an authhash all of the time).
-daz