BleepingComputer.com: Networking Newbie

HI
I am running a wireless network between 7 friends of mine. We have mobile 3.5G connection which gives us superfast surfing and we are sharing that one connection through a wifi router. This wifi router is security enabled. But we doubt that someother friends of ours have stolen our password and are using our network. We tried changing our password but they somehow get that. Now i would like to authorize only specific IPs so that none other can access our net except assigned IPs. Is it possible to do so?
We have a bandlux R100 wifi router running.
Help is appreciated.

The solution to your problem is something called a MAC Address Filter. In simple terms, every computer's network card has its own unique number on it called a MAC Address. If you go into your router configuration on turn on MAC filtering, and enter only the MAC Addresses of the computers of the friends you want to have access, all other requests from your unwanted friends will be denied (they will not be able to use your internet). However, I would like to give you a further explanation on how to do this but while trying to search for your router, all the results came up in Arabic. I do not know if it is the brand name or what, but if you dont not know how to configure it, post back and I will walk you through it the best I can.