invoice split

Hi,

When trying to create a invoice with reference to an order and delivery (ie, one invoice with reference to both order and delivery), the invoice is getting splitted. When checked the split analysis found the reason as...

boldSplit due to different header data

Fld Name

$000000001 $000000002

Combination criteria in the bi 00308030104772967 D13 00308030565347824D13

Number of foreign trade data i 0000482908 0000482909 bold

what is the reason for the above split..? how to rectify it..?

Regards,

Rahul.