Are you connecting to a USB 1.0 port or is it USB 2.0? Lots of computers out there have USB, but unless you have a newer computer, the port you've plugged into may be USB 1.0, which runs at approximately 12 mbps, roughly equivalent to bi-directional IEEE 1284 LPT ports. As for USB 2.0, is should run as fast as 400 mbps, quite a difference.
Also, your problem may be what you're printing. If a simple page prints faster as a page heavily filled with graphics, then is it a question of program speed, connection speed or printer processing speed?