I'm using an external 500GB hard drive NTFS with MKV and AVI video files plugged in the a USB port on this Sony device. In Media Player, MKV files play fine, most AVI also play fine, some do not. These same AVI that wont play on this Sony NSZ_GS7 will play fine when on another media player device, so I know the files are good. Message says files are corrupted or not supported. Anyone know why some AVI files play and some do not?