This is in reference to the BizTalk EDI DB in your BizTalk 2006 Environment. We were facing issues while including this database in out daily maintenance plan (Backup) and this was due to its compatibility level set to 70 originally by Microsoft. After reading some articles at http://blog.biztalk-info.com/archive/2007/07/14/SQL_Server_Compatibility_Mode_for_BaseEDI_and_HIPAA_accelerator.aspx and contacting Microsoft support about the issues, they has to same reply to change the compatibility level from 70 to 90 and there should be no issues for backups.

EXEC sp_dbcmptlevel BizTalkEDIDb 90;

some compatibility basics:

65  = sql server 6.5
70 = sql server 7
80 = sql server 2000
90 = sql server 2005
100 = sql server 2008

OR change is using the SQL Server Management Studio: