Users are no longer advancing along the access levels within a subscription plan

I had the site setup on a test server and ( with a subscription play setup to drip-feed 20 or so days of content to our subscribers. This worked fine

I now have the site on it's live domain and the drip feeding seemed to work fine for the first couple of days.

It no longer works at all on either the live or test domain.

Users remain on day 1 if registering for an account, or on the day they were set to if manually assigned a level via the admin tools

Your help with this would be much appreciated

Matt Hinson