I think it's mainly because it's on a port by itself. The T1 doesn't use the power portion of the USB port, just the data. It gets it's power from the wall wart. It might be picking up the noise/interference from the keyboard. Other ppl that use a powered usb hub, it's usually the only device on the hub.
E: As an aside; Ppl resort to powered usb hubs to avoid OS shenanigans where most modern OS will try to save as much power as possible by shutting or semi-powering the ports. Win Vista/7/8 and OS X are known culprits.
I guess it's the interference since T1 is wall plug power.