Help! Firecard not recognized...

Hi All
Really hope someone here can help me out with this, its driving me mad.

I've just bought a Firecard and am having real trouble getting Windows to work with it. It has worked once or twice but only after a total format. As soon as I put the menu etc back on it I get a 'Device not recognized' message on my PC the next time I plug the USB in. These are the files I have on the card at present:

Udisk_eng_1_45.sav
Udisk_eng_1_45.nds
xmenu.dat
DSYSTEM folder containing GLOBAL, LASTSAVE and SAVETYPE

I have spotted that some other firmware downloads seem to include other files such as MK5_PassMe.nds, AUTORUN and MK5-dsmouse.nds

Do I need any of these? Or is there another reason why i can't get it working?

Many thanks fo any help
mnut