Thanks. Now I have a different problem. I set Time Capsule up according to the manual instructions - ethernet wire from cable modem to TC and configured as the wi-fi router. The green light is on but now I can't connect to the internet. I spent all afternoon on the phone with three different Comcast service technicians and they all claim that my internet hardware is functioning although am still unable to connect. The last tech had me run the ethernet wire directly from the modem to our laptop and we were finally able to get internet access, but not when I reconfigure to wi-fi. They claim that the problem is with the Apple product. I've run through the diagnostics several times and have re-booted and re-connected the modem multiple times to reset but no luck. I'm hardwired now but would like to get the wi-fi up and running.
Rename the wireless to something else..
Or check.. if you are using the TC in bridge. That will be the wrong setup.. you should have the TC in router mode.
Name the wireless differently to what you have the express.
If it doesn't work.. just press reset and try again.. now you know it does work with the cable modem..
Turn off the cable modem is the most important part of the setup.. it has to have time to reset the MAC address.. restart the modem and plug in the TC in router mode. It must be connected to WAN port.
I would use the 5.6 utility, as the v6 in lion or Mountain Lion has toyland feel to it. Not a utility at all..