Hi, I have a 5.1 system with Dolby® Digital-, DTS®- en Dolby® Pro Logic® II-decoder. On some of my dvd's, there is a 6.1 dts version available, and of course a normal 5.1 version. Witch one should I choose, knowing I have only have a 5.1 system, buth with a DTS decoder. Thanks a lot for your help!!