Ok, problem solved...
For some reason, sabayon was not connecting to the internet via the router, so I ran the set up wizard on my router and it connected fine. If anyone else has connection problems on set up, you mightwant to try this.
As for the knetwork manager - it looks to be bugged. I was connected and talking to my router, but the network manager was saying that the device wasn't even on. Same for the networks config in KDE - according to that, my ra0 link wasn't even active - it was and it works. KDE's network stuff all seems to be bugged. If you are using the RT2500 driver, Sabayon will recognise and load it fine, despite what the GUI is telling you. So ignore it.
Make sure you # rc-update add net.ra0 default
and it should be fine. If not, restart your router or run the set up wizard on it again.