Argument "" isn't numeric in sprintf at /usr/local/share/perl/5.10.0/FS/cust_bill.pm line 2358.
Argument "" isn't numeric in subtraction (-) at /usr/local/share/perl/5.10.0/FS/cust_bill.pm line 2359.
Argument "" isn't numeric in addition (+) at /usr/local/share/perl/5.10.0/FS/cust_main.pm line 2788.