10.7.3 not downloading client updates

Hi I have been trying to follow this Walkthrough http://www.machone.co.uk/blog/?p=290. I know its a 10.6 walkthrough to make the 10.6 server serve updates to the clients. I managed to get as far as enabling software update and change the servers DNS settings. That I got working on the 10.6 server. I couldnt make the macs access the server, now its an old server so after four hours of trying I gave up and went onto the new server mainly because the guy before me dicked around with it so much that nothing really works.

So I ventured out got a 10.7 server running on a Mac mini and decided to follow the same walkthrough again with the DNS settings already in place. Now the server successfuly manages to update itself through software update from Apple. But in server admin it wont download any client updates? Its really frustrating me now and it seems it may be a bug. As I cannot figure out why it doesnt work....

Please any help would be great.

Thank you

JC