usb device drawing too much power

[stickleback pro]

I have a Macbook 13" dual core 2.2gHz running OSX 10.5.
I use a MBox audio interface (USB) and usb broadband modem. Other usb devices include memory stick and external hard drive (Lacie). I also use a powered hub. These have all worked very well for 6 months.
In the past few days I started to get the usb device drawing too much power message. I tried each usb device on their own which didn't work. Even the small memory stick received the same message. I have tried the Lacie hard drive on a different computer and it works fine.
I tried the PRAM reset, hardware diagnostic but no change.
It also seems to be getting worse.
I now get the message when nothing is plugged in to the ports!!!!