XBOX 360 Unsupported Format WIN7

[Atekk920]

Hello all, Im new to PMS and want to start by saying this is one hell of a piece of software when I can make it work.....I had it previously running on a Ubuntu machine and it worked flawlessly. Recently for the sake of my wife, i switched my HTPC\Media server back to Windows 7. After a fresh install and getting everything all dialed in I could not manage to make PMS work properly, any .mkv would not work with the xbox giving me the error of unsupported file format, here is hoping someone can help me out. Thanks ahead of time, a few system details below.

Win7 Ultimate
Intel core i5 750
4GB Ram
10/100 network
PMS 1.52.0