Hey “Video Guy” 
here is an example of a video file that I get the same problem.
Note - it could be any file, this is just one of them. the minute i manage to play any file and go back to the “problamatic” ones - they play without problem.
General
Complete name : D:\Gilonm Videos\From Elad\IMAX Under the Sea 3D (2009)\IMAX.Under.the.Sea.3D.mkv
Format : Matroska
File size : 7.35 GiB
Duration : 40mn 52s
Overall bit rate : 25.7 Mbps
Encoded date : UTC 2010-10-01 11:06:45
Writing application : MakeMKV v1.6.0 win(x64-release)
Writing library : libmakemkv v1.6.0 (0.7.7/0.8.1) win(x64-release)
Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4.1
Format settings, CABAC : Yes
Format settings, ReFrames : 3 frames
Codec ID : V_MPEG4/ISO/AVC
Duration : 40mn 52s
Bit rate mode : Variable
Bit rate : 23.7 Mbps
Maximum bit rate : 40.0 Mbps
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate : 23.976 fps
Standard : NTSC
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.477
Stream size : 6.77 GiB (92%)
Language : English
Audio
ID : 2
Format : DTS
Format/Info : Digital Theater Systems
Codec ID : A_DTS
Duration : 40mn 52s
Bit rate mode : Constant
Bit rate : 1 510 Kbps
Channel(s) : 6 channels
Channel positions : Front: L C R, Side: L R, LFE
Sampling rate : 48.0 KHz
Bit depth : 24 bits
Stream size : 441 MiB (6%)
Title : 3/2+1
Language : English
Text
ID : 3
Format : PGS
Codec ID : S_HDMV/PGS
Codec ID/Info : The same subtitle format used on BDs/HD-DVDs
Language : English
Menu
00:00:00.000 : en:Chapter 00
00:09:11.509 : en:Chapter 01
00:19:25.747 : en:Chapter 02
00:29:32.604 : en:Chapter 03
00:39:36.290 : en:Chapter 04
00:40:47.778 : en:Chapter 05
GeneralComplete name : D:\Gilonm Videos\From Elad\IMAX Under the Sea 3D (2009)\IMAX.Under.the.Sea.3D.mkvFormat : MatroskaFile size : 7.35 GiBDuration : 40mn 52sOverall bit rate : 25.7 MbpsEncoded date : UTC 2010-10-01 11:06:45Writing application : MakeMKV v1.6.0 win(x64-release)Writing library : libmakemkv v1.6.0 (0.7.7/0.8.1) win(x64-release)
VideoID : 1Format : AVCFormat/Info : Advanced Video CodecFormat profile : High@L4.1Format settings, CABAC : YesFormat settings, ReFrames : 3 framesCodec ID : V_MPEG4/ISO/AVCDuration : 40mn 52sBit rate mode : VariableBit rate : 23.7 MbpsMaximum bit rate : 40.0 MbpsWidth : 1 920 pixelsHeight : 1 080 pixelsDisplay aspect ratio : 16:9Frame rate : 23.976 fpsStandard : NTSCColor space : YUVChroma subsampling : 4:2:0Bit depth : 8 bitsScan type : ProgressiveBits/(Pixel*Frame) : 0.477Stream size : 6.77 GiB (92%)Language : English
AudioID : 2Format : DTSFormat/Info : Digital Theater SystemsCodec ID : A_DTSDuration : 40mn 52sBit rate mode : ConstantBit rate : 1 510 KbpsChannel(s) : 6 channelsChannel positions : Front: L C R, Side: L R, LFESampling rate : 48.0 KHzBit depth : 24 bitsStream size : 441 MiB (6%)Title : 3/2+1Language : English
TextID : 3Format : PGSCodec ID : S_HDMV/PGSCodec ID/Info : The same subtitle format used on BDs/HD-DVDsLanguage : English
Menu00:00:00.000 : en:Chapter 0000:09:11.509 : en:Chapter 0100:19:25.747 : en:Chapter 0200:29:32.604 : en:Chapter 0300:39:36.290 : en:Chapter 0400:40:47.778 : en:Chapter 05