I bit the bullet and returned my 8 month old box to Humax. No amount of Betas or new software has fixed the not coming out of sleep, in fact it's made it worse because it had started randomly rebooting.
I'm annoyed because we've lost all our recordings (which has mainly upset the kids because they've lost a load of films) but we had to do something.
I'll keep you all posted as to the result, fingers crossed.