Bonjour, Quicktime, iPodService, etc., are part of each iTunes download I have seen.
The network tech at Futureshop did say he thought the problem could be the absence of Bonjour and I checked that. I gather Bonjour (mDNSResponder.exe) needs to be running. Now it seems Multicast Streams needs to be enabled so that Bonjour can work properly. I guess my point is that most people would not have a clue about that. Most techs I talked to did not know about that either. D-link should know about that. That's just my opinion.
Is this the cause of so many folks having these iTunes connection issues for devices. I don't know but I have seen a lot of posts blaming the last 10.0 version of iTunes. You can see that in the Apple forums.
So if Multicast Streams must be enabled on the router and is not by default on all or some routers, I think people should know about that. The Mac store tech did not know about that and he had seen issues like that before. In his case, is that because Apple routers have it enabled out of the box? I don't know.
I eventually stumbled upon it. If that helps some others with similar problems that's a bonus. The way I look at it, every day you can learn something new or solve a problem is a good day.