As you may know, DBCC CHECKDB (and some of the other DBCC CHECK*) commands use an internal database snapshot to get a transactionally consistent view of the database (if you didn't, see my blog post CHECKDB From Every Angle: Complete description of all CHECKDB stages for an explanation). It's entirely possible that the database snapshot may grow and run out of space, causing the DBCC command to fail, when the database has a lot of updates running concurrently with the DBCC command (see the blog post Database snapshots – when things go wrong for some examples of this happening). There have also been some nasty bugs in SQL Server and in Windows that can cause the database snapshot to fail, and possibly cause SQL Server to hang when DBCC CHECKDB is running multi-threaded.

These bugs have been fixed and are available in a variety of ways. Suresh Kandoth, an old friend and Senior Escalation Engineer in PSS, has published a nice post that summarizes the various bugs, along with associated KB articles and release vehicle details. Check it out at Sparse File Errors: 1450 or 665 due to file fragmentation: Fixes and Workarounds.