XDJ-R1 not loading tracks properly

I've not long purchased a xdj r1, the issues I'm having are when playing tracks off of the usb flash drive, some play ok, but some randomly play other tracks not the one I've chosen, like it will display the name of the track I select but play another track instead,.. also cutting off tracks randomly half way through them playing. The usb is formatted properly for the r1 to recognise, I just don't understand why its messing up like this, so frustrating. Any help would be greatly appreciated. Thanks