ASRock ION 3D 152B. HDMI out for video and audio.

Sound fine and picture quality is great but when playing Blu Ray films the image judders. The sound stays fine just the video affected. DVDs are fine. Tried with both PowerDVD 10 Ultra 3D and Media Player Classic. Using Windows 7 Pro 64 Bit and have also formatted and installed Windows XP 32 Bit but still the same. Using Symantec Endpoint protection but still have the same problem even when it isn't installed. Using all the latest drivers from ASRock's website. And before anyone asks I have tried different Blu Rays, all originals, all have the same problem.

Any help or suggestions would be appreciated.