just quickly i was disappointed about xbmc not playing 3d sbs files then i remembered about the external player being a total noob and not knowing much about changing config files i managed to get this setup working so i thought id share
sView is a free 3d easy to use player
http://www.sview.ru/en
i ran this got it playing my SBS .mkv files the way i wanted
then on windows 7 x64 in
\AppData\Roaming\Xbmc\userdata
.....windows x86 is probably a different folder i dont know.....
i made a new text file saved it as playercorefactory.xml
inside i put
<playercorefactory>
<players>
<player name="SView" type="ExternalPlayer" audio="true" video="true">
<filename>C:\Program Files\sView 2009\sView.exe</filename>
<args>"{1}" --fullscreen /close</args>
<hidexbmc>false</hidexbmc>
<hideconsole>false</hideconsole>
<warpcursor>none</warpcursor>
</player>
</players>
<rules action="prepend">
<rule filetypes="mkv" filename=".*sbs*" player="sview"/>
</rules>
</playercorefactory>
then where i have my 3d SBS files stored i add to each movies file name sbs
so example
movie is jackass 3d.mkv i changed it to jackass 3d sbs.mkv
and it works im so happy
i love xbmc