WD TV Live SMP - stuttering and freezing when streaming from home network

Recently got a Netgear N600 dual band wifi router/dsl modem.  300 + 300 MB

When I set it up, it connected to the shared folders on both of my Windows 7 computers upstairs and streamed the videos very nicely via wifi.  (workgroup = WORKGROUP).

Then the next day, with no changes made to the unit, the WD SMP would list the home network folders in my list of content sources, but would not allow me to connect to them.

I went to the computers upstairs to check my settings, and all are fine, and the computers share to each other just fine.

I tried doing a factory reset after reading a few posts here about others with this issue, only to find that, after the factory reset, I can connect to my shared folders now, but they stutter awfully now, unplayable!

I have tried this via wifi and a gig wired connection, same thing!  Why did this work perfectly before, but not now?  It’s not a problem with my router, as it had enough bandwidth to flawlessly stream my high quality mkvs and low quality xvids the first day I had it set up.

Does anyone have any ideas?  

Thanks

edit:  I must clarify, I have no BluRay or HD media, I am ripping to Xvid and HKV of varying qualities of my personal DVD collection…

I may have figured out the issue here.  After I yanked my Linksys range extender out of the wall, seems to be working fine.

I will keep testing for a day or two more and mark this resolved.