White, the only thing I can think of is to back track the po and the postings of when they were paid to make sure everything was entered right. It sounds like it has something to do with a date that was entered. Either on the original po or when it was posted. It should just let you click on each individual line to see it and look if anything is out of range or looks wrong or if something wasn't checked.
If all else fails go to that stupid question box and type in "hey stupid quickbooks" jj type in "po complete report shows open. See if that helps. I bought that program for my sister's business so I am trying to picture it as opposed to the one I use for our business. I don't use quickbooks for ours, just at my sister's. I am fed up with it so I came up with a better

for her (I mean me) to use at the start of the year.
Let me know okay. I will have to leave soon for an appointment though.