I need help with my wireless internet?

I have an airport extreme base station wireless router. Before that I had the plain old linksys router that nearly every store has. When I was using the linksys router, every device in our house connected to the internet. Now however, with a much more capable router, some of our devices will not connect to the internet. We have 2 ipod touches, two MacBooks, a nook color and a ps3. currently, the two ipods and two computers will connect, but the nook and the ps3 will not. For instance if i unplug the router, then the ps3 will work, but one of the macbooks will not. we often have to reset the router each time we want a device to run, but that should not be the case. Each device has the correct password saved on them and has connected to the internet at least once in the past week. It is getting really frustrating. Any ideas?