I encountered same when I was watching some "According to Jim" episodes on Roku Channel Live TV.
Try pressing the up or down arrow (to change channels) and then back to the Martha Stewart Channel. Sometimes this worked for me, other times not.
Weird because sometimes the same episode would play correctly but at other times it would not. (since the series just plays in a loop could just catch it again later if it wasn't working properly).
If you are getting the same quality each time for a particular episode, likely a source issue then. (I'd like to say it would be fixed, but it likely won't be).
