That error's not repairable. This is a 2005 server? CheckDB has been succeeding until recently? I ask, cause this is usually the result of someone doing ad-hoc direct updates to the system tables, typically in SQL 2000 prior to a 2005 upgrade.

Can you check the error log, see if there's any mention that the catalog/system tables in that database have been directly updated. Error will appear right at the point SQL brings the DB online.

Can you run the following and post the full and complete output?

DBCC CHECKDB (<Database Name>) WITH NO_INFOMSGS, ALL_ERRORMSGS

As for following Paul's blog, I would strongly advise that you do not make any changes to the system tables at the moment. This is not exactly the same error as he talks about there (he's talking about missing references, this is an incorrect reference), and one of the two objects appears to be a system object.

Hacking the system tables without knowing exactly what you're doing can result in worse damage.