1. They didn't actually renew. Don't just hit the renew button and walk away. Look at the new due date to make sure the renewal went through. Our system will tell you if it can't renew the item(s) you want.
2. They were renewed after the due date. If an item is renewed after it was due, our system will look at how many days late it was and add the appropriate amount to your account.
For example, let's say a DVD that has a $1.50/day late fee was due back on a Monday and renewed on a Wednesday. Wednesday is the second day it is late, so, while the item will still renew, $3.00 in late fines will be added to your account.