If you take off streaming from backend, you have to edit your /etc/fstab on the MD in question and add forcedirectio as a mount option, note sure if this will help you though, see topic below for where to edit:
http://forum.linuxmce.org/index.php?topic=3203.0I was getting freezing and issues changing channels on my MD and bringing up the guide, but it seemed to be related to the use of VDPAU NORMAL playback setting used, as when I used HIGH QUALITY instead, the issue went away; this is with both a 9400 card and on board 9300 on separate machines, and tested using either auto or specifying vdpau for the respective MD's. I have not looked at it further since getting it working on a few days back, got caught up in the christmas season with my family.
Hope this is of any help