(Yes, Kimberly's lecturing again…)

Here's something that I've seen crop up a lot recently on corruption forums:

Server: Msg 602, Level 21, State 50, Line 1
Could not find row in sysindexes for database ID 10, object ID 1, index ID 1. Run DBCC CHECKTABLE on sysindexes.

This isn't corruption - it comes from trying to attach a 2005 database to a 2000 server. If you try to restore a 2005 database on a 2000 server, you'll see:

Server: Msg 3169, Level 16, State 1, Line 1
The backed-up database has on-disk structure version 611. The server supports version 539 and cannot restore or upgrade this database.
Server: Msg 3013, Level 16, State 1, Line 1
RESTORE DATABASE is terminating abnormally.

This gives a more useful error. Basically, SQL Server is not up-level compatible in terms of the database physical structures. A SQL 2000 server cannot understand the new structures that are in a SQL 2005 database. There's a lot of confusion about this, and why setting database compatibility level is not the same as the physical version of the database. My blog post Search Engine Q&A #13: Difference between database version and database compatibility level has more details.

Trying to do the same thing with a 2008 database on a 2005 server is a bit better. For the attach we get:

Msg 1813, Level 16, State 2, Line 1
Could not open new database 'Dbmaint2008'. CREATE DATABASE is aborted.
Msg 948, Level 20, State 1, Line 1
The database 'Dbmaint2008' cannot be opened because it is version 655. This server supports version 612 and earlier. A downgrade path is not supported.

(Note that 611 is the physical version for all SQL Server 2005 builds, but if VARDECIMAL is enabled, the version gets bumped by one to 612 – long story…)

But the restore error is still a little cryptic:

Msg 3241, Level 16, State 7, Line 1
The media family on device 'c:\sqlskills\dbmaint2008.bck' is incorrectly formed. SQL Server cannot process this media family.
Msg 3013, Level 16, State 1, Line 1
RESTORE DATABASE is terminating abnormally.

Bottom line – you can't attach a higher-version database to a lower-version server.