WMC/WMP delays video 200ms behind audio.

When playing back .TS , .M2TS container files (H.264 video format) the audio is approx. 200ms ahead of the video when using WMP/WMC. If I use 3rd party Cyberlink PowerDVD software, the file plays back fine. No sync issues. If I copy the .TS .M2TS files to my Win 7 pro 64bit rigs, their media center/Media player software plays the files back fine. No sync issues.

After scouring various forums, I seen where some folks went to Device Manager - Sound - Properties - Advanced and unchecked the 'Allow applications to take exclusive control of the device.' and 'Give exclusive mode applications priority' boxes. After trying this, the same .TS file plays back with the audio in sync with the video for WMC/WMP, but now the bitstream is just 2 channel AC-3. (so it appears that Windows is now using the default 2 channel audio settings)

I then went to the device manager - sound - Configuration - and set the output to 5.1 surround. This results in an uncompressed PCM audio signal on the hdmi output to the receiver.. all channels active, but if video with stereo only is played, then sound only comes out the L/R speakers despite the receiver showing all five active. So Bit streaming the audio is disabled when setting the sound options to anything other than default stereo.. (at least with WMC/ WMP) I don't want the sound decoded in the computer, I want it bitstreamed to my flagship denon receiver with its fancy DAC's..

I want to use WMC on 8.1 Pro 64bit and bitstream DD 5.1 AC-3 over the HDMI cable using the integrated igpu/audio.

One other curious symptom:
If I'm playing back the .TS file with WMC, its audio is 200ms ahead of the video, if I use the mouse to jump ahead or
behind, or if I change from full mode to windowed mode, the sound syncs up... To me, this smells like a driver issue.. I've been browsing the Sound Threads in this forum and seen no one else having these symptoms..

Note: I am using the i7 5775C broadwell cpu, so this may put a different spin on the issue... Just looking for some troubleshooting assistance to narrow down this one minor glitch...

(Netflix stuff plays fine, unprotected .wtv files play fine)

This is a weird one... I'm really looking forward to putting this system to use with a Ceton InfiniTV6 cablecard tuner..
thx
NKOST