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…

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.