you need to setup fusion.

Please follow the youtube video that will show u step by step to setup navi-X.

http://www.youtube.com/watch?v=HaX7fcQJ1jw
simple step
1) go to system>file manager. add source
2) key in address: http://fusion.xbmchub.com
3) go to setting>add on>install from zip file>fusion>program and click navi-x (it will auto install in the program option)
4) Go to programs and you will see navi-X sppeared the screen and volar enjoy and play with all the function.

Hope that help.

You may also install icefilem . try googling it the step is same as I mentioned.