Yeah, I'm almost 100% sure that Sony anything will not play an Mkv file. I've had the same issue with ripping my bluray collection so that I may stream it to my PS3. I've found that mp4 or m2ts formats work best. I use a software called aunsoft blu-ray video converter ultimate for this and it works great. I've done this manually with handbrake and various other applications but it is too time consuming.