If it's working I wouldn't worry about it. Some wireless routers block some types of broadcast and multicast packets. I had 2 shields in a taco bell today connected to their wireless and they couldn't see each other. That's a common setup at public hotspots, it doesn't allow 1 wireless client to talk to the other wireless clients, only out to the internet. So technically you could buy a cheap wireless router that does that at home. That's one reason for the list.
The other reason I can think of is WMM which is QOS for wireless. Not all routers have it. Not all people think it's the best thing for wireless, but I will tell you that when you share your connection with 10 friends, WMM is key. If you are the only one at your house on your own wireless, it doesn't much matter.
My 2 cents.