I was able to follow the wizard directions and enable the WN3000RP and get a live internet connection, but within two minutes the connection fails and I get an error message that there is another device on the network with the same IP Address. I had connected the Extender directly to the computer as directed for the configuration, but should I then disconnect the network cable and try to reconnect the HOMENETWORK_ext?
Banyardi - Did you solve this? Just guessing here, but sounds like your PC is trying to connect to the WN3000 both via wifi and the ethernet cable used to configure it, hence the "two devices" error. Either disconnect the ethernet cable and connect to the network/internet via wifi, or turn off the wifi access in your pc and connect via the ethernet cable.
I just installed a WN3000 today. Setup was accomplished by pushing the Push n' Connect buttons per setup instructions - first on the Netgear N300 gateway, then on the WN3000. My home and guest networks are both established and secure through the extender. And, strong!! Guest network is for a second building with rooms about 120' from the extender. 5 bars throughout the second building!!