When I play DVD films they have started juddering every 5 seconds. I have an Acer laptop, XP SP2 and this happens in both PowerDvD 6 and Windows Media Player so I doubt that it is software related. They played normally up until last week and I have made no changes since. Nothing else is running when the problem happens and I've tried disabling Anti-Virus and Firewall with no effect. I have also copied the DVD to the hard drive and played it from there but with the same problem so it is not the DVD player. This used to work fine. Any ideas?