The USB ports on the Apple Keyboard are USB 1.1 only so they’ll work with most USB 1.1 PC devices. In some cases, there may not be enough power to use both ports on the keyboard.
Some USB devices use a lot of current.
VAIO VGN-Z590N // Core 2 Duo 2.53GHz | 4GB RAM | 320GB 7200 RPM | 802.11a/b/g/n | Bluetooth 2.0 HP TC1100 // 1.1GHz | 1.5GB RAM | 100GB 5400RPM | 802.11a/b/g | Bluetooth 1.2 Daily Gear // Sony Ericsson X1i | Panasonic Lumix ZS3 Digicam
i have tested many things and no problem at all so far:
cameras hubs
etc…..