Patrons - Displaying as overdue when books have been returned

I have a small issue but it's annoying me. I have a couple of patrons who are displaying as overdue, on the patron page.
They have however returned their books, and when I go into their individual profiles it says they don't have any due books.
Yet it continues to display on the patron grid as overdue.
How can I fix this?

>1 WattleGumLibrary: Hi there, thanks for letting me know! Can you email me with the names of the patrons you're having trouble with? tinycat@librarything.com.

I'll be happy to dig into this for you!

EDIT: I see you did indeed email us those details already, I'll reply there!