Because the principal "DBO" does not exist problem solution

An error occurred while deleting a publication during replication:

Cannot Execute as the Database Principal because the principal "DBO" does not exist, this type of principal cannot be impersonated, or you do not have permission.

Solution:

This database is directly recovered from a 2k5 backup file to the 2k8 instance without any other settings.

This error occurs when I log on to sa.

 

  use master 
 go 
 exec  sys. sp_dbcmptlevel  @ dbname  = n  'mydb   ',  @ new_cmptlevel  =  90   go   use   mydb   go   exec  sys. sp_changedbowner  @ loginame  = SA,  @ Map  =  '  dbowner   '  go