unable to join home wifi network with iphone 3gs or ipod touch

My Netgear WNR2000 router is up to date with firmware and my Dell laptop can connect to it wirelessly now that I have configured it to Windows 7.

My iphone 3gs and ipod touch see the wifi SSDI name, but when I try to configure, reset, or update the devices or the router, after following numerous tech support suggestions, I only get an error message "unable to join network." I have the patience to keep trying, but have had no luck so far, any advice would be greatly appreciated!

My devices:

Netgear WNR2000v1 wireless n router, set to WPA2 (AES) Personal

Dell Studio XPS laptop with Windows 7

iphone 3gs, 8GB model MC640LL, iOS version 4.2.1

ipod touch 32GB model MC008LL, 3rd generation, iOS version 3.1.3

Also, not sure how to access 2.4GHz settings on router, as I saw advice to try to disable the 40MHz setting as it is not supported by iphones/ipods and may reduce interference. Though, I am guessing my error message may not be related to interference...

If it is an encryption issue I could try resetting my security level. Is there a lower level that I should be comfortable with leaving my wifi set to (I would rather not use WEP).

Thank you for any advice!