Home Network :: Unauthorized Name And Password Change?

In short, I had the following problem in the past but it solved itself when people physically left the area. Now they are back, the problem is occurring and this time I have as many router settings as I can find to maybe aid in the solution.This is the problem:We have a wireless network where the physical equipment is not available to users and yet, the local network name and password continues to be changed wirelessly FROM say, "ABC network" with network password "ABC secret password" to "Jimmy's Network" and network password "some new string of letters and numbers". (we know who Jimmy is but will not approach him until we learn if this situation is inadvertent on his part or more purposeful, which we doubt as of now)Cisco Lynksys Wireless-N Home Router WRT120N[CODE]