USBI’m missing something here, I just know it. Maybe one of you guys can figure it out?

I have a powered USB 2.0 hi-speed hub which I plug into the back of my new Linux/Windows PC. The hub works beautifully both in a powered or unpowered state – as long as the PC is already on. When I switch off the PC, unplug the hub and then plug it back in again, the PC’s power LED lights up but the machine itself can then no longer be switched on or off – it is as if it is now in some sort of ‘semi-powered’ state. Obviously it would seem that it is drawing power from the powered USB hub, but why the heck would it be doing this in the first place?

I am now running the hub unpowered, but this isn’t really the ideal situation. Or rather, I should say that this isn’t the ideal situation because I don’t know what the heck is causing this situation! :)

So, any ideas?