Ben's just in denial, I tried to tell him... He would insist on buying an unbranded, untested handset onto the Orange network he's just asking for problems!
I know it'll be difficult, but have you tried using your Z1010 to see if it's the same? Those clips were brought down on my Sanyo, which doesn't use PV. I wondered if it may just be the player on the 6680 handset and not the actual content.
I'm pretty sure O's position on it would be if it's working for others on "official" equipment then it must be something to do with the actual HS not the DL source.