Had a look at the Microsoft web site
- usual first line of info.
SP1 has been around for some time - presumably world wide.
Not quite sure if you want to discuss the issue with your support provider, but install the update, but before you do, get to know and understand your backup systems.
Even try a restore, as if you were dry running a disaster recovery scenario.
Windows Small Business Server 2003 Service Pack 1
Updated: June 6, 2005
Stay current with the latest software and security updates with this important set of updates. With Windows Small Business Server 2003 Service Pack 1, you can take advantage of several key product improvements, including:
• Enhanced security and performance
• Increased reliability
• Improved productivity and collaboration