Yes, but it's not date-based.
SQL Server 2005 does not support compatibility level 65 (SQL Server 6.5)
SQL Server 2008 does not support compatibility level 70 (SQL Server 7)
p.s. Please in future post new questions in a new thread rather than resurrecting an old thread.
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)SQL In The Wild
: Discussions on DB performance with occasional diversions into recoverability
We walk in the dark places no others will enter
We stand on the bridge and no one may pass