Install CCCP. It should solve most of you playback problems.
I used to install numerous of single decoders and filters and still had a few movies that could not be played.
If I knew CCCP would be that good I would have used it a long time ago.
+1000
Once CCCP pack installed, instead of Ffdshow mpeg-2 decoder, prefer for your HD Mpeg-2 videos, MPV decoder as Directshow Mpeg-2 decoder, then set it with Bob de-interlaced, and prefer overlay as video render :
Best results and not any frame dropped anymore, even in 50fps !