I seem to be experiencing a similar issue, with a a new Samsung UE32ES5505 (all recent updates installed).

Buffering can't keep up with playback. The issue seems to occur primarily when playing back higher quality 16:9 content.

Low quality 4:3 formats, and some 16:9, seem to playback fine.

Internet connection is synchronous, stable and fast. Also, this issue only occurs on my UE32ES5505.