Sorry, could you clarify exactly which submission process you have chosen under Scheduled Conference Setup 2.1? Are you accepting file uploads, or are you expecting authors to just revise their abstracts as they appear in the Abstract field? Technically, if you've chosen "Abstract submission only; no file upload", then the author shouldn't be able to upload a file at all -- I've added this as a bug report here
. If you have any comments on the bug report itself, I'd love to hear them.