Del Lee (1/21/2013)
To me, it sounds like the corruption is still there and can reappear when that page or pages become "reallocated."
No. When a page is reallocated, it's rewritten, so anything on that page is overwritten.
Secondly, one of the articles tells how to enable checksums, but doesn't say how to check if they are already enabled. I've only been here less than a year, so I have no way of knowing if the database was originally created in version 2005 or if it was sooner.
page_verify in sys.databases
Thirdly, if I've only seen this once and not repeatedly, is it necessary to look into possible problems with the I/O subsystem?
Yes. Corruption doesn't appear from nowhere for no reason. Something went wrong to cause it at all.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability