AFAIK this device use the bcm43xx chipset from broadcom....
wich is fully supported and natively installed on BT
im sure of this fact.....i check on specification list........
802.11g F5D7051 man: 050d dev: 7051 USB Broadcom Bcm43xx
that means you don't need to use ndiswrapper or any ralink driver(rt2570)
please remove ndiswrapper module from memory
plug your adapter
you will see your adapter as ethX
hope it helps