Mine has done that about 25% of the time I plug it in, on various computers, Windows and Linux. If it connects as USB 1.1 just unplug and re-plug and it'll almost always negotiate as USB 2.0 the second time around. It hasn't happened to me yet in PR1.1 but I've only plugged in USB a couple times since upgrading.

Also, if you have a USB 1.0 device (like keyboard, mouse, printer) on the USB hub it could sometimes force all devices on that hub to go slow.