Play back with live SMP is choppy and delayed

Okay, I have been using WD products for over 2 years now.  Started with the WDTV, on to the WDTV live, the plus, Hub, and now the live smp.  Up until I started using the live SMp, I didn’t havde this problem.  Movies played smoothly.  I mainly bought this one because of the built in wi-fi.  When I try to play back any kind of file it starts smooth, gets choppy, then stops all together.  Sometimes I can stop and then resume playback, and it will play for 10 or 15 more minutes, and then repeat the above issue.  This is on wi-fi, and eathernet cord.  I’ve tried clearing the cash, turning off network share media server.  And nothing seems to work.  Set up is.  cisco E1000 router, connected to a modem. from the router is a 4TB my book world edition, 3TB my book live, and live wire first box.  Living room 20 feet away.  second livewire box, with live SMP, WDTV live plus, and xbox360.  Those are the ones that play the movies choppy, well the SMP, not the WDTV live plus, that still works just fine.  I also have a second live SMP connected to the first livewire box, but it’s connected with a ethernet cord going in to a second bedroom.  Suggestions, ideas please?  Doesn’t seem worth the headache if the wi fi is still going to be choppie and always stopping or interrupted.

Wait, this happens with wire and wireless connection and ANY movie file? You might have a bad device? I can stream movies, wire connection,  without any issue.

No, just on the one when I try to go wireless, or hard wire it through the WD live wire set.  But the one that is connected to first live wire box, that is conected to router and modem, plays movies with no issues.  It’s strange, because the second live SMP that is connected to WD live wire second box, is choppy when playing movies, but the WD live Plus that is connected to the same piece plays movies just fine.  Quite a mystery.;