WD10EADS-00M2B0 slow

I have a Name WD10EADS-00M2B0 (Green 1TB) in my WHS box, which is giving me problems.  It seems that any video stored on this drive has playback issues including stuttering and slow loading.  I have 2 other WD10EADS-00L5B1 in my machine that do not have these issues.  Is there a problem with my drive or are these newer 00M2B0 drives too slow for streaming video.  I ran chkdsk which reported no errors.  I also copy a video off that drive onto another and playback is fine.

Any ideas?

i guess this is a problem with my disk, so I will rma it.