AR Invoice Import

SOLVED

I feel like I should know this, but for some reason I'm struggling with this VI job.  I am importing into AR Invoice Data Entry.  My file has over 400 lines in it.  What I want to happen is have the import assign the Next new invoice number, once.  However, what it does is assign an new invoice number EVERY time the dollar amount changes in the file.  The only way around it that I could find was to do a Runtime Assign.  I could do this but would prefer not to if at all possible. 

Am I missing something or is this just the way it works???

Thanks

Sue