First of all, it is not a Dlink problem, per se. It is almost every NAS device on the market. It is soley the problem with upgrading to iTunes 10.5. They had the exact same problem on an earlier 10.x release until it was updated.
I had my new 320 working and the first night I setup iTunes it worked great, the next day I upgraded to 10.5 and could not figure it out until I downgraded back to 10.3.1 and everything worked.
Until I get an ipad and need iOS 5.0 that requires iTunes 10.5, I am quite happy with 10.3.1 and my NAS with iTunes server working the way it is supposed to.
As much as Microsoft tics me off all of the time, Apple does it even more so. Think "goverment" but you are happy to pay for their ****, when we deal with these companies and their glitchy updates.