Another reviewer (I'll delete), I pointed a file play HD MKV problem following the latest firmware updates for LG BD370. The latest version of the FW seems to have fixed this bug. The BD370 platinum becomes therefore, besides being an excellent reader of Blu-ray, DVD and dvix an even more amazing machine because capable of playing high definition MKV ... (careful though: still no compatibility with discs hard and NTFS formatted USB key (so no file beyond 4 G0 - but you can burn them to blank media)