Hi,
Just to clarify, did you actually download the driver from the SATO support page? The drivers that came with the installation disk could be outdated, which the mort reliable option is always the manufacturer's website. The symptoms you are describing fall right in line with what an outdated driver can cause.
However, if that does not do the trick, it's very possible that there might be a problem with that USB port. Have you had any issue with any other devices plugged into that port in the past? Or are you able to try the printer on another computer?