Recently, we found out that HP Data Protector had an update, and I took for granted that this update would make the product more compatible with SQL Server 2008 - but it still doesn't support SQL Server 2008 without installing the Backwards Compatibility Pack from SQL Server 2005. 
Not entirely such a pain, but just be aware, HPDP fans, that this warning message 'SQL DMO Component is not available which will cause MS SQL Integration to fail' really means to say you should download the SQL Server 2005 Backwards Compatibility Pack (SQLServer2005_BC_x.msi). If you read the fine print of their Support Manual, you`ll notice on page twelve, point seven, that the SQL DMO download is required.

If you haven't installed the Backwards Compatibilty Pack first, then when using HP Data Protector with SQL Server 2008, you will see this error (HR 0x80040154] Class not registered): 

Or notice this error in your Debug.txt (set this in properties) in your Sysroot\Program Files\Omniback folder:

25/03/2010 11:27:48 AM  OB2BAR_Main.796.2948 ["integ/sql_7/sql7_dmo.cpp /main/hsl_dp61/hsl_hpit2_2/1":288] A.06.11 b243
[SQL7_Login] Failed creating object instance. Err code: -2147221164, REGDB_E_CLASSNOTREG
Function trace (currentLevel=3):
 Level  3: SQL7_Login()
 Level  2: SQL7_CheckConfig()
 Level  1: SQL7_Config()
 Level  0: main()

When Installing the SQL Server 2005 Backwards compatibility Setup, you only need the SQL DMO object components for HP Data Protector to work correctly with SQL Server 2008.