Suspect this is something that should be really easy to fix because no-one else here, at TGB or on the Linksys forum seem to be having the same problem!
The dma2200 will find all of the other wireless networks in our neighboorhood but it won't find ours.
I recently added a new laptop to the network and it found it straight away and connected effortlessly.
I tried moving the dma2200 closer to the router (only 4 metres away and direct line of sight) to test signal strength and again absolutely nothing.
Any suggestions are most welcome.