Probleam listing blogs in the blog directory page

Has anyone had a problem regarding the listing of blogs in the blog directory page? We have just had http://www.wp.mu set up the hosting of a new site for us using MU/Buddypress/BBpress but we are getting a problem with the themes... I think.

The story so far is that we have set up test memberships with a blog each and for some reason these blogs are not been listed on the blogs page apart from the main site.

Today I changed the theme I was using (BuddyPress Corporate Child) to another theme (BuddyPress Business 2) and all the blogs are now being listed on the blog directory page which made me think that the Corp Child theme may be broken. So to test this I switched back from the Business 2 theme back to the Corp Child theme and guess what... all the blogs where listed this time.

I was really pleased so asked a few friends to see if they could see the blogs listed from different locations but whilst I could see all the blogs on the directory page my friends could not, even when I changed the themes and they refreshed and even cleared there cache.

Is this a server or installation issue because I can’t see how I can possibly fix it from my end?