Airport Utility fails to see Airport Extreme Only an Older Base Station no longer connected

Very weird what's happened... earlier this morning there was a power failure (none of my 2 computers were ON, and they are plugged in thru UPS with power surge/outage capabilities).

I turned my old Macbook Pro (2007) and everythign is fine. My Mac Pro (2008) is fine but it can't connect to the internet.

I've resetted both the modem and the Airport Extreme Base Station.

I've restarted and resetted the PRAM on my Mac Pro.

I've tried many times to diagnose it/change settings/create new network with Network and Airport Utility to no avail.

When I open Airport Utility on the Macbook Pro, it shows the Airport Extreme and it all looks fine... when I open Airport Utility on the Mac Pro, it only sees an old Snow/Graphite Base Station I haven't had plugged in in a log time. It doesn't see anything else.

I've tried trashing the Airport Utility preferences as well... but still nothing. The Wif Fi icon shows a '!'. When I click on it, the pull down menu shows an "Alert: No Internet Connection", but it still shows my network (and the neighbours' network) and it even has the check mark next to my network... ???

I'm running 10.8.5 and Airport Utility 6.3.1.

Please. Help.