Static will not change unless you update it with an automation policy. So you have dynamic filters, static filters with no automation policy update schedule, and static filters with an automation policy update schedule.
But really, it's better to just make a dynamic filter.
OS Name is contained in the AeX AC Identification data class under the OS Name property, and OS Revision (e.g. Service Pack) is contained under the same data class under the OS Revision policy. If you're ever not sure about stuff like this, just poke around in the Resource Manager for a computer until you find what you want to look at.
You'll want to create a new filter using the query builder for Computer resources (query tab, click Base Query, choose Computer from the drop-down, click OK).
Then, under Filter Expressions, add condition, AND, [AeX AC Identification].[OS Name] Equals Microsoft Windows XP
Add condition, AND, [AeX AC Identification].[OS Revision] NotEqualTo Service Pack 3.
Click Save Changes and you should get the proper results of Windows XP computers running a Service Pack other than SP3.
Does this help?