ANSWER:

The database page has become corrupt. Normally this wouldn’t be that big a deal as you could probably repair the corrupt page by using DBCC CHECKDB. However this is a system object page (a page which contains system objects) so the database will need to be restored from a full backup.

You can run DBCC CHECKDB for the database in question to see the exact object which is corrupt to ensure that it is a system object.

Odds are this is because of a problem with your disks. Either a disk is failing or a RAID controller is failing.

by mrdenny from http://serverfault.com/questions/382470