It looks like it may have partially uninstalled. Perhaps the uninstall script is not robust enough to detect if portions have already been uninstalled.
What I would recommend doing is this:
1) make sure it is not uninstalled.
2) try manually loading the data model in again, and then uninstalling it. You can manually load the data model by going into the sql/ directory of the package and using psql or sqlplus to load in the data model. Load the create script. Then try uninstalling again.
3) If that doesn't work, I would post a bug in the Bugtracker.
Hope that helps. I know this is frustrating, but you're going to learn a lot about this all works in the process!
