DVD issue

[cavey]

Hello all,

Sorry if i posted this in the wrong place, as this is a slightly a few problems into one. I bought Stargate Atlantis S2 (Region 1) DVD a few years back and was re-watching them again from disc 1 to 5.

In the past, there were no problems (however to note in the past i was on XP professional). However this round, the first 3 discs were fine. Playback of the last 2 discs had some problems. it took a long time to scan before playback (about 5 mins). During this time, the pc began to hang (pc still works but it seems to freeze up (unless you wait 5 mins or eject the disc))

Each DVD have up to 4 episodes, the first 3 discs played fine, but once it got to the last episode, it will go through the scan feature, if lucky, it will go through, but playback will be jerky, or it will restart the DVD.This happens on 2 of the PCs running Windows 7.

However if i run clonedvd, the DVD rips fine! Though much slower at certain points.
Add on
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I found that the last disc cant be ripped, after an hour and at 77% it said bad sector found and cannot continue

So just wondering, what could be the real cause? If the dvds were spoiled, i would have changed them years ago. Suspecting drive issue but 2 pcs with different DVD-Roms with the same issue? Any other thoughts on this? Running AnyDVD HD 6.7.8.0 on OS Windows 7 Pro 64 bit (dont have XP OS to try to see if it is an OS issue )

Thank you.