Ultrapeering is network decided. If you have a good connection speed, lots of free slots & available bandwidth for uploading & downlding then it increases your chances of becoming an ultrapeer. This happens when the network needs more ultrapeers. Perhaps there's enough ultrapeers at this very moment in your general area. You'll know if you're an ultrapeer if you check the connections page & find more many connections more than normal.

BTW if you see a brick wall in front of the blue world icon at the bottom of LW's interface which represents a firewall problem then you won't be able to become an ultrapeer.