My library also lends DVDs.They're due in 3 weeks from the time I borrow them but it used to be one week.The system hasn't been fully updated as the library receipts still indicate the DVD is due after one week.Since everything is computerized,the automated system kicks after a week has passed and delivers an "overdue" message.The library needs to update the automated system to accurately reflect due dates.I assume this is what is happening with others,or similar situations.Peace.