I have the same exact problem
I think what happends is the winamp plug-in wants to do everything by playlists.., seeing as it can't get any playlist stuff at all, it can't get the song..
what I mean is, the plug-in gets an amount of the playlist and if you tell it to get 0 playlist tracks, it still gets one part of the playlist, the current track, and rather then getting the track name the normal way by looking at the winamp window.., it just uses the playlist information is already got
since the winamp_spam plug-in doesn't support anything to do with playlists, your not going to be able to get the track or anything
hopefully the author will include playlist support in a later plug-in, he has already said he will work on in this topichttp://www.r1ch.net/forum/index.php?topic=97.0
and thank you (the author) for the time you have already put into this, it would be nice to have playlist support and everything, but control is my major concern.., if it werent for this plug-in, I'd be stuck using winamp still