Iphone 4s not seeing wifi

We recently moved and we set up our motorola surfboard cable modem with our apple extreme router. before the move, my iphone and my husband's iphone worked fine connecting to wifi through the extreme. we had not changed any settings, but were unable to connect to the wifi network with our iphones, my iphone 4 and my husband's iphone 4s. We still are able to connect with our iPad, and with our macbook. we have tried resetting phones, resetting router to factory settings, changing radio mode on extreme... just about everything. the wifi still will not come up on the list of available networks on our phones, but we are able to connect to other wifi networks in other places.

Please help!

thanks