We have a form that is a table where we have the Income lines adding off the total of the verified monthly income.  We are using the normal SUM formula on the field and it is working fine:

However, the users should be able to delete the rows.  Essentially this is income information for a benefit application and if the user wishes to edit things they can.  They also should be able to delete all the rows and submit the empty form (thus deleting the income lines through workflow).

The delete and everything works great, however because of the calculation field I cannot delete all the rows and submit (the calculation field was a recent addition).  So if I remove both the rows I get:

How can I get around this and let the Form get submitted.  I also cannot put 0 in this field because 0 verified means 0 where nothing means the verification has not happened yet.

Also note that the field works fine when you have no lines to start with.  If you get to the form with no pre-existing Income lines then you can add lines and everything works.  It seems to be when you get to the form and the table populates via a lookup that I get the error.

Thanks,

Chris