Thanks I'll take a look at that one too.
I haven't managed to boot my new iMac from any external hard drive with a Supeduper! Clone yet though. Not my new USB drive or my older FireWire drives which have always worked in the past with previous iMacs (using a thunderbolt to FW adaptor). Well, actually it will boot from the FW drives but takes 30 mins to do so and then nothing will open once it has booted.
Not having much luck so far
Especially seeing as my Carbonite back up no longer works either and my iPos has decided to stop working as well.
Al.