Is pgadmin server component listening on IPv6 as well or only IPv4. Windows will always return IPv6 look back address for localhost if both are available apparently.
That was sounding like a real possibility when I read it before going to bed last night. Unfortunately, when I tested this morning I found it's not the cause, at least for me. My Windows 7 box does have v6 enabled (and does return ::1 for localhost) but pgAdmin still worked fine. I even tried completely disabling v4, but it still worked.
I think the next step is to try disabling the proxy. If that works, we then need to figure out a real solution, but at least it'll point us in the right direction.
