hupdate.
took it back to P4U 3 weeks ago, explained what had happened.
they sent it off no faffing about, and said they would call me when they recieved it back.
didn't hear anything for 2 weeks, so i went in to see what was going on, and they brought the phone out that they had recieved back 3 days after it had been sent... they didn't even attempt to ring me (the letter saying 'dear customer, your phone has been returned to P4U' was inside the package still...)
but the engineers report said 'faulty electronic component'... so that narrows it down alot
but it seems to be up and running again
and they didn't delete any of my files either