[ic] Authorizenet losing order number

[sstreich]

I'm using IC 4.8.1 w/ authorizenet.pm 2.1 apache server w/ freebsd 4.3
Everytime I submit a order I receive an error stating "invoice cannot be
left blank",  in checking the error logs tmp/icdebug the only field empty
that is required by authorizenet is the Invoice_Num.
Here is where I get confused, In the authorizenet module it calls Trans_ID
=> $actual->order_id and then Auth_Code => $actual->{auth_code},
x_Invoice_Num => $actual->{mv_order_number},
The order_id number is showing fine on the email invoices if postal is
selected as payment.
Is there a setting to get the invoice number to read as the mv_order_number
?
Any pointers or suggestions would be appreciated.
I couldn't find any comments on the board concerning this particular problem
so I imagine it's somthing I have done.
Thanks
Steve