Error: The database is not consistent with the expected database schema version

After upgrade from standard license to an enterprise version of SharePoint 2007, one of my customers Starts to notice a repeated error in the event log under the application section.

Event Type: Error
Event Source: Windows SharePoint Services 3
Event Category: Topology
Event ID: 5617

The error massage was:

The schema version (3.0.149.0) of the database SharePoint_AdminContent_xxxxxxxxxxxxxxxxxx on x64a is not consistent with the expected database schema version (3.0.150.0) on XXX. Connections to this database from this server have been blocked to avoid data loss. Upgrade the web front end or the content database to ensure that these versions match

The Solution was very simple:

stsadm -o upgrade -inplace -url http://{relevant central_admin_url}

In my case that seemed to have solved the problem.