Open a receipt window for each client that has a zero balance with entries and check them off.  They will all go away.

Hey CSPOA_Paul,

Have a look at this article from our Sage Knowledgebase that addresses your issue.

Customer has a 0.00 balance but shows a balance on Aged Receivables Report

Hi, I am having this issue as well, and none of the solutions in the kb you posted had any effect. If I close my financial year will they become permanent?

What is the date you used for the receipt to clear out the transactions?  If you used a date within the current month, the customers will still show on the aging.