1 out of 3 copies Bad

I just bought a lite-on (411s) DVD-+r drive. I have started to copy all my dvd’s (100+) so that I have an archive. Anyway, I use CloneDVD (The latest) and DVD Decryptor to make my copies. It seems for no apparent reason that 1 of 3 copies are bad.
What I mean by bad is that they get fragmented looking when I play them, and this only appears towards the 1hour + mark while watching them.
My DVD player is an older Panasonic A110, and I have used both Fujitsu and TDK (2x) and burned them at 2X-2.4X. Either media has the same issues. I have even tried to copy a copy that a friens made, and I get the same issue.
My Desktop PC is a Clone with 768MB Ram, 2.1 Ghz Processor, Running a fully patched XP. I have the Anti-virus software turned off, and the system shows very little resource useage.

Does any-one have some starter tips on what to do to decrease the amount of waste, or is it normal till I find the right media to lose 1/3. Also, is Ritek a better media for this then the TDK?

Thanks for any insight you may have,

That player is listed @ http://www.dvdrhelp.com/ it doesn’t look to play burned dvd’s that well although they do not have the Media that you are using listed. It seems as though the Media best suited to that player is Ricoh. Ricoh matches up well with the Liteon drives also. I don’t know who makes TDK or Fujitsu but I imagine it’s not Ricoh You can find out by testing with KProbe. I would try Imation or Fugi both made by Ricoh.

So it is a media problem. I will look at the Ricoh media after the next batch is done.