Finally this problem is fixed in Threshold 2 update.

I don't wanted everyone to see my Video folder. The point of that screenshot is that process Com Surrogate is using my HDD 85,7MB/s when I open that folder.

This is what happens after I open my Video folder
http://i.imgur.com/iibBJJK.png
My PC is unuseable then. Please this need to be fixed.
I've already located those .mkv files which are causing it...

Still not fixed

I have the exact same problem. It is driving me crazy. When I open my Video folder where is a lot of 15GB+ mkv files it takes literaly ages to load thumbnails and lot of them won't load ever. During...