Samsung BD-D8500M Subtitle issue - flickering lines

[Sparrowsabre7]

I've noticed when playing a DVD with subtitles on my Blu-ray player (not sure if it happens on Blu-rays too) that every few lines or so, a horizontal line flickers along the screen to the left of where the subtitle appears, as though extrapolated from the text (though the text is unchanged).

It's far from a big deal, but it's a little irksome as it does affect one's attention while watching a film. It's definitely not the DVD as it's happened on several I've played.

Anyone have any clue as to what this could be or what's causing it? The only thing Google shows me RE subtitles and blu-rays is a flickering problem due to dynamic contrast which affects the whole screen.