Anyone else having trouble using Home Sharing on AppleTV (3rd Gen) on wired network?

First my setup: I'm on a Mid-2010 MacBook Pro, D-Link DIR-615 Router, AppleTV (3rd Gen).

Problem: Couldn't connect to Home Sharing via the AppleTV.

I was having serious trouble getting Home Sharing working on my AppleTV (3rd Gen). I spent an hour on the phone with Apple Tech Support. Then, after forwarding the proper ports (http://support.apple.com/kb/HT2463?viewlocale=en_US), spending another hour and a half with D-Link. Then I even called my ISP. Anyway, after A LOT of futzing around, I finally realized that Home Sharing is working on my iPhone (4S), so maybe it's a wifi thing. I unplugged the ethernet cable from my AppleTV and connected it to my wireless network. Keep in mind, same network, just now it's connected via a different channel (wireless now versus wired before).

Suddenly, works just fine, no issues at all.

What's going on? Anyone have any idea? My port forwarding is now not even set to the correct IP address of my AppleTV (was ...100 when it was wired, but on wifi it grabbed ...103). It would be great to know what's going on. Also, hopefully this helps someone else having the same problem.