fatxplorer question

[KungFuzion]

I have a 128gb usb flash drive & formatted it as memory unit in fatxplorer giving me the full space. When I connect it to my 360 it still shows as unformatted even though it shows up in fatxplorer as a memory unit. Horizon see's it as a memory unit too. If you do this on the xbox it only gives you the 32gb limit which is shit but the xbox does recognise it this way.

I want the usb flash frive to hold my profile/saves etc, as I have multiple 500gb hdd in the slim enclosures holding games, XBLA, homebrew and so on. Am I missing something? My xbox is a rgh3 trinity. Thanks