http://daap.sourceforge.net/ was a site I came to after googling. I know nothing about this and cannot recall this exact problem. I do notice that this was something particularly associated with iTunes 4 and wonder if that is what you are using , or have you updated to iTunes 5 or 6 (which is the latest).
I do reacall a slightly similar problem with version 5.0, but after going to 5.0.1 the problem dissapeared. Just a thought.....