Consolidating Jobs for Statements

I recently worked out that the statements were not working properly because the invoices were being billed at a job level. No problem, change the 'Consolidate Jobs on Sales Transactions' to checked. Big problem, the job now appears on the transaction line, but it is not really 'there'. A null value is returned from a script lookup. And then when I change the orginal customer:job to the customer, I loose all the job information for that invoice and then have to re-enter the job on each line item. A very slow process. I have even tried enabling and disabling the