ACH payments "To ACH" cause duplicate number warning

Hello,

When we create a new ACH payment, and choose the checking account we use to make ACH payments from, Netsuite auto-numbers the check "To ACH", and we get a Duplicate Number warning that says:

[INDENT]VendPymt number To ACH is already used. You may enter a new number below, then click "Save", or click "Leave" to leave the number unchanged.
[/INDENT]

It then presents a new number. When I click "Save" it warns that the record has already been saved - but if I click "Leave" it keeps the record numbered "To ACH".

The problem seems intermittent - it might have to do with what the previously selected default payment account was. But it crops up a lot. The workaround is to go through the extra Duplicate/Already Saved warnings. However, we like to email vouchers to vendors and need to remember not to do this until the real serial number is re-saved, otherwise they get a "To ACH" payment "number" - an error we've made quite a few times.