Copying copies of a dvd

Hi all, it’s pc challenged here.
I have some dvds that copied with glitchs in them, ie. freeze frame then play or freeze up completely. I re-copied one of the worse ones and it now plays flawlessly. I am going to re-copy the rest of the glitchy ones. My question is this, when I originaly ripped and copied them it took on average 35-40 minutes per movie to complete. Now to copy them, ( I’m using my copies ), it takes over 60 minutes just to rip them and another 10 minutes to burn. Do I need to re-rip them or just copy them to my hard drive and then burn them?
I am using Memorex 16X +R.( not the best medium according to this site)
but I did slow down my burn speed to 8X and that seemed to help immensly.(a tip recieved from you guys)

Your drive may have reset back to PIO mode…
http://club.cdfreaks.com/f61/troubleshooting-enabling-checking-dma-windows-vista-xp-2000-me-9x-101616/

Thanks tOnee1, I’ll check it out!!

You may also be doing multiple reads to try and fix the errors. I’d re-rip them from the originals if I were you.