For those of you who are not yet aware, Microsoft have discovered a bug in Service Pack 2 for MOSS. Once service pack 2 is installed, it resets the license of SharePoint server to the 180 day trial license. This means that if not remedied, the license could expire and access to the environment would be blocked.
The official blog post by the MOSS team is here –
The problem can be fixed by re-entering the license key (in the ‘Convert License Type’ page of Central Administration) or waiting for a hotfix which should be posted on the Microsoft support site sometime soon.
Hope this helps!