RDR-VX525 Question

I recently purchased a RDR - VX525 Sony DVD/VCR Recorder and every DVD  R I put in gets a disk error.  I can play DVDs but cannot put a blank one in to record or dubb a VCR tape.  I am able to play DVD on it but not about to keep a blank disk in.  I have tried all kings.  DVD - R or +  EVEN KEEP purchasing new one.  If anyone has one of these and could help me I would apprecate it.