If you guys use WIFI I can highly recommend to test your routers wifi channels to see which is best. In my router it's from 1-13, 20 or 40 MHz and the difference can be hugh if you have lots of WIFI users in your neighborhood. On PC you can see what they use with a little program from http://www.wifichannelscanner.com/. Don't mind the %status, just check what channels they use and don't use any of them.
I spent two hours testing them all and it was well spent time, the speed can drop a lot if you have use the same as others when the traffic is high. I could get 50 mb on one and 3 on another when I tested on my iMac (in PC mode).