i just stumbled upon a really interesting bug in the proc cr_import_content in /packages/acs-content-repository/tcl/revision-procs.tcl:
When i'm creating a new revision of an image the title and mime_type is correctly passed to the corresponding pl/sql proc, but when i'm creating an entire new image, these parameters are not passed to image.new() in oracle, but actually are passed to image__new() in postgres. So I think they have to added to the revision-procs-oracle.xql file.