I just installed my G5 iMac (Maxed out on Ram and HD,) everything works great except that neither private or commercial DVDs' wont mount however, the System DVDs' do. When you put one in there is a few of the usual sounds from the drive but nothing happens until it eventually spits it out, my iMac G4 plays them OK. It burns and plays CDs' without any problems.

Does any one have any ideas please?

Adrian