You may have an invoice that is showing as not yet posted, but is actually posted.
We are currently evaluating this issue and will update this article when we have more information.
Steps to Duplicate
1. Go to Accounts Payable 2. Go to Vendor 3. Select the invoice 4. Notice is says not yet posted 5. Go to the GL distribution tab 6. Select the "DR/CR" buttons, the distribution posted and we can see it on reports