ipod not connecting to internet

i have tried everything to get my ipod to connect to my wifi at home. it used to work and now doesn't connect at all. it has found my router's name but the 3bars at the top of the ipod signalling wifi strength does not appear, even though i am sitting beside the router. safari does not open.

i have reset the network settings, powered on/off ipod and router, i've been to the apple store and seen someone at the genius bar and we confirmed that it was not a hardware problem. ipod's software is up to date. i have also reset my router settings to allow for more devices and it does not have a problem connecting my iphone. my other ipod or my laptops to the internet. did anyone else out there experience this problem? how did you fix this? any suggestions would help! help!