problem with printing to a usb printer using php_printer.dll

I have been trying to get this small bit of code to work using my dell photo printer 720 (or any usb printer, for that matter): <?php $handle = printer_open("Dell Photo Printer 720"); // printer being the name of the printer printer_set_option($handle, PRINTER_MODE, "raw"); printer_set_option($handle, PRINTER_COPIES, "3"); // i want 3 copies printer_write($handle, "This is a test"); printer_close($handle); ?> The printer is initialized, and the job is spooled; however, before it prints anything the print manager deletes the job! I have tries this on several different computers running IIS and Apache with the same results. I tried it from the command line too, with the same results. I'm about to lose my mind. This code works fine if I use a non-usb printer. Any ideas? Sean Rowe