Using Sony branded dvd+rw discs (ha!), I burned some divx files to watch on my RDR870 - no problem.

I then wanted to use the disc to transfer some stuff on the HDD - it didn't want to know. I couldn't format the disc and couldn't record directly to it. Even using the PC to thoroughly erase the disc couldn't make it usable as far the Sony was concerned!

Does this mean that once a disc has been used on a PC, it becomes unusable on the Sony?!?

It shouldn't do. My experience is that the PVR doesn't like disks that have been formatted or erased on the PC, but it's always been quite happy to reformat them itself, whatever state they are in to start with. I've been using Tesco own-brand DVD +RW disks happily for a long time now.

Maybe it's a compatibilty thing because you are using Sony disks in a Sony recorder

I've had bad experiences with the Sony DVD+RW discs too (in fact I've got 7 out of a box of 10 still sealed and unopened. My LG PVR just doesn't want to know. I have no problems with any other brand but Sony is a no-no.

sorry guys but it's not a coincidence - it's all discs cooked on a pc - what now?

PC Problems?

Thoughts and questions:

1. Do you have access to another PC with a DVD burner? Will it write to one of your PC-erased disks? (If it won't, it suggests a PC problem.)

2. What software (and function) did you use to "thoroughly erase the disc"? I don't know if this will lead anywhere, but it might be a clue. I use Nero's "Quick-erase rewritable disc".

3. Have you got -- or can you get -- any DVD video files on your PC (the folders of .VOB files etc. rather than DivX files) ? Try burning one to disk, then seeing if the PVR will (a) play it, and then (b) format it.

marfjam - some answers

1. yes, 2; yes they both do

2. nero's full-erase rewritable disc (tried quickerase first)

3. did that; burnt dvd of some weird monster movie, played fine but, again, would not format!

Hmmm...

The finger is starting to point rather strongly at the PVR. I presume it does still format new disks OK?

Unfortunately, getting any sense out of Sony Technical "Support" is always a great challenge. Anybody else got any ideas? (Software glitch, maybe?)

The only other test I can think of is a lot harder to set up. It needs access to another Sony PVR that does reformat used disks. You could then try some mix-and-match scenarios moving the disks around between the PC and the two PVRs.

I don't suppose the box is still under warrenty, is it?

OK thanks to all but I've given up! I'm going to use the same half-dozen only used by the Sony and no others.