Sound issue through HDMI

Hi,
i'm connecting windows XBMC trough HDMI to Panasonic TV...
if i connect HDMI first, then launch XBMC, sound ok, but when i launch XBMC before connect HDMI - no sound and no option for Panasonic. Second method is more comfortable for me, so is any fix for this?

P.S. XBMC v10 (and v11... maybe) didn't had this issue