I have seen that script and it looks old. Don't quote me, but I think it's that old it is trying to connect to the old Shoutcast V1 server.
Drawing data from an XML will give you lag, and the current song will most likely be posted in the chat room when the song is finished.
The script is signing in to so much information, no wonder it's giving you problems.
I will post a simple radio bot here shortly that I use through my network of radio stations. Just have to tidy it up for you to edit.
Cheers
