IBM Multi-Port USB Hub User Manual page 12

Understanding device-usage guidelines
Before you begin using the devices connected to the hub, be sure to note the following
device-usage guidelines:
Do not activate resource-intensive devices at the same time because USB
limitations might cause a degradation in the performance and the speed of the
devices. For example, do not start a USB scanner while you are using a USB
camera. Instead, close the application for the camera; then start the scanner.
The hub printer port works only with printers; it does not work with other parallel
devices. However, the printer port does support bidirectional communication
between the printer and the computer.
Use only a standard or USB mouse with the hub. USB limitations prevent the
use of serial input devices, such as a mouse, through the serial port. Use a USB
graphic tablet because a standard graphic tablet might work like a serial mouse.
1-8 IBM Multi-Port USB Hub