@Satcomer I just found that the DVDs work fine on a different machine. So it must be the HW. Internal/external data cable? Well this is the standard Mac Book pro mid 2009, as far as I know everything is still inside, so it must be internal :-)
The strange thing is that CDs play properly, but not...
Hi gtackett, did you ever found a fix for this issue? I recently upgraded from Snow Leopard to Mavericks and just today I found that my recorded DVD-R are being rejected. CDs are ok. Really annoying thing.