I was using a Ridata 512MB with the original Xdrive I, it won't work. Likewise with the Xdrive II, I tried it with the same type of card and it is a no go too. Seems to me that the manufacturer simply ignored the outcry made by many Xdrive I owners. This is a really sad example of ignorance ;(
No Xdrives for me ever again (unless they wake up their idea)