You have to uninstall the Toshiba Bluetooth stack and install the Microsoft Bluetooth stack to make the scrolling features of the magic mouse work on Toshiba products.
When i try to install the MS stack i get an error on my Qosmio G50. If anybody knows another Bluetooth stack that works with this driver please post it.
Or better yet Toshiba, why don't you whip something up for us. I'm sure you have an egghead somewhere that can get this fixed in an hour.
The magic mouse windows drivers are here
http://www.trackpadmagic.com/