Hi Grant - the truth is that they are equally as stumped as me. Prism have first class customer service and immediately sent me out another Orpheus so i could eliminate their hardware as the issue.
Their suggestions matched mine, and we've tried everything to no avail. It's almost certainly some kind of odd issue where something has become corrupt, but i can't find out what is responsible or what caused it in the first place.
The list of what might have changed should be finite.
... those guys may be able to give you a list of all the files, or there may be one in an Installer log or a Help file somewhere.
Thanks for this Grant. Appreciate the help. I'll pass these on in the meantime and see if it sparks any ideas.
I should point out that i also tried downloading the latest version of Cubase (i was using version 4 but grabbed the 6.5 trial to try that out) but the issue still persists. I'm hoping i can sort this without the hassle of running a clean install etc.