I have get the first time this to. Maybe it is one of this 2 problems:
My failures were:
- do not give the localhost IP for the webservice if it's running on your server here with ipconfig /all (windows) you can get the real IP adress. Because localhost is the android emulator ip
- I had a URL from outside but i was in a firm which uses a proxy. So in he emulator nothing came into. There is a way to start the emaulator.exe with -httpproxy (like that just type in the shell emulator.exe ? then you can see it what conditions are allowed.) But in one forum post they said that this proxy implementation at the emulator is buggy.