I have no problems playing PAL or NTSC HD MKV or TS files on my iMac but I have run into a problem with 50 fps files from Europe when I play with VLC, which seems to be my only freeware option for these files. Basically what happens is the file sticks, then jumps ahead, stutters a bit, sticks...Is there a setting in VLC that can help with this? My iMac is about 3 years old and I am running Snow Leopard so perhaps the problem is not with VLC but the OS. Can anyone recommend some possible solutions?