Connecting iPod nano (1G) to PM G4 AGP via USB

When I connect my iPod to my G4, iTunes "warns" me
that I am connecting through a "low-speed USB 1.1
port" - this did not happen in the past, and I do not
know how my USB interface reverted to 1.1 (it came
with 2.0 installed) nor do I know how to update the
appropriate firmware or software in order to have USB
2 again...

I checked with the Apple System Profiler which
confirms that my max transfer speed on the USB bus is
12Mbps, although I'm unsure where if anywhere it
actually lists the USB version...

Can anyone enlighten me?