I know the error I have is local to my installation of Moodle because i've used the Moodle Mobile test-app successfully.
On my own server, I installed Moodle 2.6.1, enabled web services (saved changes), created a test user.
during the authentication process, I'm told that either the url or the port is wrong. I added a port number I have checked the url several times (asked my wife to check my typing too) - since my server is Linux I have checked for capitalisation.
I've tried searching for similar cases, to see which port I should use, and drawn a blank (I think a port isn't required is it?).
I'm running PHP 5.4.21 on Linux. My version of Moodle runs fine on a 'normal' box.
Would someone be kind enough to have a think for me, please?