BuddyPress Create a site assigns an invalid URL

I have posted a question on BuddyPress too, but hopefully someone here might have the answer:

’m running a subdirectory-based multisite setup using W3.9.1 and BuddyPress 2.0.1

Going into the dialogue, it shows: Sitename, followed by the URL of the multisite setup ibstherapists.co.uk/ and then the input field, so I enter ‘test’ expecting to access the site as ibstherapists.co.uk/test

However, once the create a site is completed, the actual URL displayed is http:///test/ – no sign of the ibstherapists.co.uk and of course the url is invalid.

I’m new to Buddypress, so it is quite possible I’ve missed something (although I couldn’t find anything!). Could someone please give me some pointers in the right direction?