QUOTE(Bomb Bloke @ Mar 1 2007, 12:03 AM)

Argh! You guys don't get it, do you? MKV, AVI, it makes no difference. Both of them will stutter under certain settings and both of them will play fine the rest of the time. You want some concrete reasons, provide the encoding details.
As contingent says, the in-testing MPlayer builds provide much better performance then the old one.
not trying to be rude but what do you suggest the optimum setting that we should use!? although for me I have no problem what so ever except with 1 mkv movie and to mention that I'm using the default XBMC settings.
my problematic movie info
Format : Matroska
File size : 700 MiB
PlayTime : 1h 47mn
Bit rate : 914 Kbps
Encoded date : UTC 2006-08-30 22:14:58
Writing application : VirtualDubMod 1.5.10.2 (build 2542/release)
Writing library : libebml-0.7.5 & libmatroska-0.7.7
Video #0
Codec : Intel H.264
Codec/Info : Intel H.264
PlayTime : 1h 46mn
Width : 768 pixels
Height : 432 pixels
Aspect ratio : 16/9
Frame rate : 23.976 fps
Resolution : 12 bits
Audio #0
Codec : Vorbis
Bit rate mode : VBR
Channel(s) : 2 channels
Sampling rate : 48 KHz