If you do decide to upgrade to DP 8, stop Data Protector and make a copy of your Internal Database, and keep it in a safe place
UNIX
/var/opt/omni/server/db40
Windows 2003
Program Files -> Omniback -> db40
Windows 2008
Program Data -> Omniback -> db40
While clean, new installs of DP 8 have not had a great deal of problems, upgrades from previous versions have been a challenge, and a number of people have reverted back to their previous version of DP. Having a saved copy of the IDB would make that task easier for you
I normally recommend that, when dealing with a new version of Data Protector, you wait to do the upgrade until, at least, the first set of patches are released
If you decide that this is not the right time to go to DP 8, at least get yourself onto a Supported version, 6.21 or 7.01, otherwise, the Response Center will probably not be able to do much to help you with any problems
Jean-Michel is quite right in one regard, there is really no easier way to handle the IDB catalog