Windows 7 - Windows Media Player glitch at start of playback

Hello, we are using Windows Media Player 12 on our PC's running Windows 7 Professional 32-bit. They are Dell PC's, i5 processors, 4GB RAM and have tested with various video cards from nVidia and ATI.

When starting playback of a WMV file, there is a quick "flash" of the background color that you can set in WMP. This usually happens when the 2nd and subsequent files in the playlist start playing. Or you can play one WMV file and put it on loop to replicate the problem.

We have seen this on several different PC's running several different video cards.

The WMV's are encoded as 720p @ 8Mbps. The length does not matter. The upcoming file can be short or long, and we see the background flash at the beginning of each one almost every time.

We also run a software player that utilizes DirectShow to play back video files. When we run the WMV's through this player, it stutters on that same part of the files... the beginning.

The files all play back fine in VLC. No glitches or stuttering.

I have checked the files in an editor, re-encoded them at different bit rates, done all kinds of problem solving and determined it is WMP/DirectShow causing these playback issues.

Does anyone know what might be causing this and how to make it play back smoothly without this glitch? A service I might be running and could turn off maybe?

We have tried the exact same files on a Windows XP system and there is no issue with playback at all.

Thanks!