[LAU] USB has power even when PC is shut down?

I upgraded my home PC to AMD64 dual core and the motherboard is ASUS M2N-E Socket AM2 NVIDIA nForce 570 Ultra: http://www.newegg.com/Product/Product.aspx?Item=N82E16813131022 I've an M-Audio Midisport 4x4 MIDI box connected to the PC via USB. On my old system (AthlonXP 2000, I forgot what kind of motherboard), when the system was turned off, everything went dark. But on the new system, the Midisport stays powered up even after the PC is turned off. I can tell it's up because the green LED is still blinking. The PC really is off, the disks are stopped, no moving parts move, everything is cold. Well, I guess this is more of a hardware question, but still, what's the deal with USB on these new motherboards? Is the bus still powered even after the system is turned off? -- Florin Andrei http://florin.myip.org/