Hi, I just found a file using the FourCC code FLV4 and which doesn't play by default. However, by editing the codecs.conf to include FLV4 to the ffvp6 codec it works. Maybe this fourcc should be added to it - it shouldn't be a real problem (after all it is more or less a minor adjustment). To be precisely - according to mkvinfo - it has the following: (FourCC: FLV4, 0x34564c46) -- GMX DSL: Internet, Telefon und Entertainment f?r nur 19,99 EUR/mtl.! http://portal.gmx.net/de/go/dsl02