by Dan Marsden.
nice to hear it's been useful for you - there are still a few issues with the code partly due to the complexities of using the existing Turnitin api - hopefully the new version being developed by Turnitin will be even better!
what assignment type are you using? - the new one in Moodle 2.3 or the old assignment from 2.2? - can you take a screenshot of the page the user sees when submitting a file? - are you logged in as a real student or using the "student view" option in Moodle?