I'm sorry, really don't have the time and resources to try all that right now. However, you can find plenty of similar reports on this problem here and in the AVSForum threads. Lots of different routers have been involved. Basically, if a network uses the DAP-1522, and there is a Pioneer VSX-(x)20k receiver, where x is anything from 8 to 11, the internet radio function fails after 15 to 30 minutes, as the receiver appears to drop from the network. Remove the DAP-1522 from the network and the receiver remains connected and internet radio works just fine. It's as simple as that.
Lots of users have attempted explaining this to both Pioneer and DLink, and they have just said it is the other company's problem. No one at either company has been willing to look at the problem.