Print limit

I have a data base invoice set up, where there is a subtable of linked line items (products and prices) plus a totaliser function summing all lines to give a total price.

when I go to print the invoice I seem to be unable to print more than 6 line items, no matter how many lines I have. (The summed price however is correct for all lines including the ones I can't see)

I can not alter the print area, or change the table high for instance to give more room for more lines. (Auto height selected and unable to selected fixed height to manually change height).  The only way I can do more than 6 lines is to split the invoice over two separate invoices instead.

any thoughts?