Inventor 2008 does not work with ADMS 5. You need to ugrade ADMS 5 to ADMS
2008.
You do this by uninstalling ADMS 5 (make a backup first just in case
anything goes wrong!), and installing ADMS 2008. ADMS 2008 should see your
existing vault(s) and libraries and migrate them at the end of the
installation.
At this point your vault(s) and CC libraries can still be used with Inventor
11 (once you install the Inventor 11 compatibility update for ADMS 2008 on
each Inventor 11 seat); and your vault(s) will work with Inventor 2008, but
you don't have any libraries visible to Inventor 2008 yet.
In the ADMS Console, you will see that each library is in the "Inventor 11"
partition (its in the details in the right pane when you select a library).
You can "Copy" any custom libraries to the "Inventor 2008" partition to make
them visible to Inventor 2008. However, the Inventor 11 standard content
libraries cannot be copied ... instead you need to install the 2008
libraries from the Inventor DVD/CD. Once this is done, you should see all
your libraries from Inventor 2008.
Hope this helps,
Dave Mink
Autodesk / Data Management