I'm not seeing any connection attempts in my log, or the masterserver log, from the IP you've used here, so it's possible that Ultrasurf has a problem with UDP, the transport protocol used by AC. A simple test would be to temporarily disable/remove Ultrasurf and see if the problem is fixed.
edit: Although this doesn't explain why you can see some servers.
edit: Although this doesn't explain why you can see some servers.