Printing from SCO Unix to Win98 box

I am connecting Windows 98 machines to a SCO Unix server. When running an application through Unix and I try to print from the Unix applicaion to a printer connected to a Win98 box it sometimes takes two, three and even four times sending the print job before it will print once. Printing through Windows prints every time. The printer is a HP 2100 deskjet connected to the Win98 box. Any clue as to why this works sometimes and others it will take several times before printing?