Are you using Change Tracking? That's what the syscommittab is for. If so, try disabling and reenabling Change Tracking.
If that doesn't fix it, or you're not using Change Tracking, I'd call Product Support. Could be a bug.
Paul Randal
CEO, SQLskills.com: Check out SQLskills online training!
Blog:www.SQLskills.com/blogs/paul Twitter: @PaulRandal
SQL MVP, Microsoft RD, Contributing Editor of TechNet Magazine
Author of DBCC CHECKDB/repair (and other Storage Engine) code of SQL Server 2005