When installing just the required packages under Oracle 10g I get the below errors:

Failed to create index content_content_hits_idx on liberty_content_hits:
CREATE INDEX content_content_hits_idx ON liberty_content_hits (content_id)

Failed to create index themes_layouts_module_idx on themes_layouts:
CREATE INDEX themes_layouts_module_idx ON themes_layouts (module_id)

I had a look at the tables and the indexs were automatically created - I'm guessing when the primary key was defined in the CREATE TABLE statement these were created. I'm using the CVS version which I got this morning.

Daniel - I'd simply delete those lines in the scheme_inc.php ( liberty and themes ). I'm not sure why only those are being flagged, I think I have a couple more duplicated in Firebird, but you are right that once something is set as PRIMARY then in most real databases, an index will also be created. I think these duplicates should simply be removed.