Also, good diagnostic trick (Assuming you are having the problem printing across the network):

Try plugging directly into the printer with a USB cable, unplugging the computer and the printer from the network, printing to the printer across the USB cable (may need to configure a new printer connection in the windows control panel for this to work), and seeing if the problem recurs on the USB cable. If it does not have a problem on the USB cable, then it's definitely a network issue and not a printer issue.