Unable to use wireless with airport time capsule

When I originally setup my Imac and MacBook with Time Capsule, it connected wirelessly with no problems. A couple month ago an update for Time capsule was downloaded and now I have to connect with a cable to my Time Capsule on both Imac and MacBook. I set up the airport for wireless but when I open the network type the name of the network use a WPA2 password, it shows "Connection Timeout". I reset the modem several times, used different names for the Network, use Channel 1 (not auto) but nothing seems to work! Any ideas? TIA

When I used Network Diagnostic and try to join my network and typing the correct password, I get : "This computer was unable to join the Airport Network you selected. You may have entered an incorrect paswrd or netwk name, chosen the wrong type of wireless security or u may be out of range of the base station. To change ur previuos choices click Go Back" None of these apply to my case!!!