Apple help?

Here’s my problem as clearly as I can break it down, looking for any advice.

I have a mid-2009 20″ iMac (2.66 Core 2 Duo) which I regularly run both Snow Leopard and Windows XP Professional(SP3).  I am using the Apple extended 10-key aluminum keyboard, which is relevant for my question.

When I’m booted into OSX, I can use the built-in hub on the keyboard to power essentially any USB device, like charging an iPhone.  OSX reports it is seeing 500 mA of power going to the hub.  However, when I boot into XP, suddenly the current drops to 100 mA, which is not enough for high powered USB devices.  So the issue clearly relates to XP.  I’m up to date on all drivers and other software.  The problem exists both with the extended and mini keyboards (the one that comes with the iMac).

I know I can get a powered USB hub, and I have one.  However, for the way I normally work, it would be a lot more convenient to use the keyboard hub for high powered devices.  Anyone know a solution?