The secret’s in the operating system. I successfully paired my Apple wireless keyboard and Mighty Mouse with a Lenovo S10e using a Targus USB Ultra-Mini dongle. OS: Linux Ubuntu Netbook Remix 9.1 beta. I imagine it would work with 9.04 too.
I worked for hours trying to pair the Apple keyboard under XP. Hours looking up and trying workarounds and hacks. Finally gave up.
Switched to Linux and it was apples and pairs. (See what I did there? Clever?)
Tiny netbook, right sized keyboard, and a more useful mouse. That made my Sunday.