[markbowen]

Fixed now. Had to install Total Commander and then edited sdcard/system/etc/permissions/profile.xml

Find the permission "Write_External_Storage" and there will be the permission group: "sdcard_rw"
Add another group directly under that one: <group gid="media_rw" />
Save changes made in the file and exit
Reboot your device

As per this post here :

http://forum.xda-developers.com/showthre...?t=2665128

Hope that helps someone else if they come across this post.

I can now read and write to any USB flash drive directly from within Kodi or for that matter any other App on the box.