It's hard to know. @xppx Are you 100% sure that the problem started only after upgrading to MP 1.6? By that I mean that you were playing videos no problem with MP 1.5, then you upgraded to MP 1.6 and immediately started to have the problem. No chance of any install, uninstall, patch, change in configuration of Windows or any other software or drivers that could have caused the problem? If so, the only thing I can suggest to narrow the problem is to see if MP 1.6 pre release gives you the same problem.