Page 1 of Problem with Pc Dvd, Please help?

Hello all.
Come someone help me with a problem im having???
Just recently for no apparent reason my dvd`s wont play or burn on my pc?
Im using Windows Xp pro and its been ok for ages.
When I try to play a dvd it`s all stutterery and juddery?
When I try to burn using Clone 2 it says `Failed to read dvd drive, data error (cyclic redundancy check)`. ???

I havent a clue, Ive tried different dvd`s etc and ive gone through all `windows help` since and it just seems worse.
Please Help
Much Appreciated

...just to add ive cleaned dvd/cd unit and all im really trying to do now is get the dvd playing without the juddering
Is there a string of settings worth me trying?
Thanks!

check the atapi/ata controller in device manager and make sure that the dvd drive isn`t set to PIO as it should be udma 2 or thereabouts (this requires knowing which ide channel its on and whether its master or slave)

Done that.
Anything else I can try with the settings?