If I play a dvd file from my hard drive, all is well. If I play the same file from a DVD in my DVD drive, the video is slow and jerky. The sound echoes like in a tin can, too. I've tried Realplayer, Winamp, Windows Media Player and Nero with the same degraded results. I'm runnung XP w/SP2, 1024 memory with a 2 gig cpu. Also have a good 256 pcie video card that has no problem playing DOOM3 with all the bells and whistles turned on. Any ideas? I need help-please!

Had a similar problem with my laptop. then Couldn't get the dvd drive to burn discs eventually. Sent to repair centre and they said the dvd drive was shot and put in a new one. All is ok now.
Have you tried burning a disc or doing a drive test with Nero. Maybe even running a lens cleaning disc etc

okay, when you're trying to playback a DVD the next time check taskmanager (press ALT+CTRL+DEL) if the CPU usuage is up to a 100% then there's something wrong in the communication between the drive and the m-board or driver curruption.

so you can do this;
open up the case
remove the cables from the drive and unplug them also from the board
attach them again (making sure they're firmly in place)
and reboot to see if the problem has changed

another option is, if you have to drives you can alwasy switch them around, adjusting the jumpers to suit

I found this thread as it seems to come close to my problem.

I have to DVD writers on my PC and both were working perfectly. I tried to play a DVD in them a couple of days ago and both have developed the same problem. They play the DVD (and CDs as well) slightly slowly and with an element of slight echo, crackle and stutter. I have checked the DVD on which I first noticed the problem with my laptop and on the DVD player with the TV. It plays perfectly there. Other DVDs exhibit the same problem - and it's pretty much the same on each player on the PC. Music and video already on the PC plays perfectly and, if I rip the music to the PC that music plays better than on the DVD player (though still not perfectly). If I try to rip the video to the hard drive, though, I only get the audio channel even though it says it's in mp4 format.

I've checked CPU usage and it is at normal levels. I have unplugged the power cables, rebooted, shut down and plugged them back. I haven't done that yet with the data cables because I find them too fiddly for my novice hands and I don't want to wreck the whole machine!

The bottom line is that this has come out of nowhere.

I am having the same problem with the added twist of it happens on my laptop and my desktop which are connected together on my home network. It also has just started within the past two weeks.

I have tried everything mentioned so far to no avail.