Some Copied DVD's don't play

[tonelokke]

I have a Pioneer DVD-RW DVR K13A drive that works fine in most cases. Cd's are no problem and original dvd's are never a problem. However some copied dvd's including ones I have copied myself don't register in the drive. As in it says 'please insert disk' when there is one in there. And for other copied dvd's it sometimes thinks they are cds.
I run Windows Xp and have no other problems. I have tried various codecs and even checked Pioneers website out but there is no mention of my specific drive.
Could someone spare a little bit of their computer genius to someone not so giften in the art of computer manipulation????? - but not a total moron either.

[SingSing]

New disc sometime has a thin layer of chemical on t. Try use lens cleaner and soft cloth to clean thge disc, and try again.

[Krispy Kritter]

What media are you using? Have you tried a different brand/type of media?

You also need to ensure you have finalised the session/closed the disc.

[Krispy Kritter]

The only reference that I can find for the k13a drive is in reference to Toshiba laptops. Apparently this is an OEM drive used by Toshiba, but I could be wrong.