iPhone 4S, Wi-Fi Connected, No Internet.

Bought iPhone 4S yesterday. (I love it, especially after a 6-year-old clamshell!)

At office and hotspots, Wi-Fi works fine. At home, Wi-Fi shows fully connected (I can even synch sibling apps on iMac and iPhone that only synch via Wi-Fi ["Things"]) but I cannot load internet via Wi-Fi.

iMac is 10.6.8.

DSL router is hard-line wired to iMac.

Two AirPort Express devices on stereos in other rooms for iTunes-rocking home.

Thought maybe AirPort Express needed to have hard-line DSL for iPhone to connect via Wi-Fi.

So, I took one from stereo and plugged into my router.

Green light on AirPort Express but still NO WI-FI LOVE.

Can someone please offer a solution to this obstacle?

Thank you very much, community!