If I'd have to give a guess it would probably have to do with the device or its connection that you have Slingplayer installed. It could be a desktop firewall or bandwidth shaping utilites that might be hindering your connection. Issues like this are pretty diffcult to determine without being more intimate with your personal computing ecosystem.
I am sure it has to do with your wireless configuration. What channel is your wlan? Do you have wide band enabled? How much security does your router have to deal with? With wireless n your neighbor's wireless can compete with yours. Find out what channels are used near you with inssider. Free program.
If you share the same channel with other networks you can have higher latency. Connecting to your neighbors on a clear channel could be faster than you on your lan.