HTPC crashes when switching AV Receiver to another source then bac

I have a HTPC (Shuttle SG33G5) running Vista Ultimate 32 Bit and JR Media
Center 12 connected to a Yami V2700 using HDMI for sound and vision (and on
to a Hitachi Plasma). All patched and up to date

The problem is Vista Crashes & Reboots (or the JR MC app hangs) if I switch
my AV Receiver from the HTPC to another source and back again if I am playing
any content using DirectShow Filters.

Typically the Vista Crash & Reboot is when I switch away and back while a
DVB-T Channel is playing. Typically the JR MC hangs when playing a Video (eg
when switching back to the HTPC you hear a Vista beep and the screen is
displaying "MC12 has stopped responding" error).

There is no problem if Video is not playing video (eg it is fine on the
Desktop, in JR Media Center's Theater View IF etc).

Any Ideas?
Thanks
Nathan