We sometimes get this message in a dialog box labeled Warning:
 
WARNING: SO# xxxxxx has an indicated deposit amount of $x.xx.
This is the deposit amount that printed on the invoice.
However, the deposits linked to this SO have an unused balance that
is zero or negative, so the invoice will post with a deposit amount of zero.
 
What the heck does that mean, and what should we do to fix it?
How can a deposit have an Unused balance of Zero?  Zero  
would mean there is no unused balance.
 
Update:
We just tried voiding the invoice.  Re-linked the deposit to the
sales order, printed a new invoice, and then tried to post it
and again, we got this message.  We routinely use the deposit system to record
Credit card payments.  Any suggestions would be appreciated.