Android : Access Basic Authentication To View A Protected Url

I'm trying to do basic authentication to view a protected url. I want to access the protected url which looks like this:

http://api.test.com/userinfo/vid?=1234. So I do the following with a WebView:

mWebView.setHttpAuthUsernamePassword("api.test.com", "", "me@test.com", "my password");
mWebView.loadUrl("http://api.test.com/userinfo/user?uid=53461");

but the authentication doesn't seem to work, I'm just getting an output error page. Am I using the WebView method correctly here?

Update:
Trying with curl: curl -u me@test.com:mypassword http://api.test.com/userinfo/user?uid=53461

and it pulls the page fine. I tried every combination of the host parameter, the owners of the api don't know what I mean by 'realm' though (and neither do I) - what info could I give them to help this along?