okay so last night i was watching the bonus disc of revenge of the sith in xbmc (all fine) - when i booted up the xbox today the disc loaded an offical dashboard on the system (turns out the disc has a demo of battlefront).
anyhow as my xbox still had the SID installer splinter cell save - i popped in my copy of splinter cell and loaded it up and reloaded the unleashed dashboard.
i then tried to FTP up a shortcut so XBMC loaded directly but i messed up the filename (^^!), so no dashboard loads at all now so i get error messages on boot up - games would still boot so i:
a) tried to reinstall the softmod - but splinter cell seems to just restart the intro (but the power light does change) and nothing is installed.
b) popped in the star wars disc to reinstall an offical dashboard - the xbox now boots into the standard dash and i've tried to reinstall the softmod but the same thing happens as in a) (splinter cell just restarts, power light changes)