Since you might want help... might as well be the blinder (swordsperson) leading the blind...
I arsked a similar question... albeit much less intelligently and for different reasons and got a response; I'm a complete moron and of no help to you here, but it is a similar question and might help.
What was helpfully mentioned was a number of options... AND a poster mentioned that with some models you could just plug your PVR into a USB port.
It sounds stupid to mention, as you've probably already done so, but maybe just search your model in the forum and see if others have asked/answered/addressed the PVR to USB port with hardware/software question already.
Probably not of any help... but I should try to recontribute that given to me.