OK, after some searching I found out: it seems that some USB controllers don't work properly with the ehci_hcd module loaded. This is a bug that should get fixed in the future.
For now, what you can do is:
a) sudo modprobe -r ehci_hcd every time you have restarted
b) add "blacklist ehci_hcd" to the /etc/modprobe.d/blacklist file
Option b makes sure the ehci_hcd module is unloaded every time you reboot. This should help until the problem is fixed.
I'll add this to the Floola Quick Guide too!