Htc error message

Hi there, I'm pretty new to xbmc, but i love it. i have installed the latest remote control app on my phone from the official xbmc people, I have followed all the online tips/guides but allas it still wont work...keep getting the same error message......I/O Exceptions (java.io.FileNotFoundException) http://my ip address and port number/jsonrpc
Any one know what i'm doing wrong here and what i need to do to sort it out??