Well just started up my Xbox 360 which has being off for a few weeks the Xbox 360 is connected to a 28' ViewSonic LCD the Xbox 360 is connected via HDMI, now before the new dashboard I had HD resolutions i.e., 720p 1080p now after the new dashboard I have PC resolutions this is causing my issue of sound, my LCD is thinking the signal is DVI not an HDMI thus giving me no sound through my speakers on the LCD, it seems I am not only having the issue but a few others are too 
http://uk.gamespot.com/pages/forums/show_msgs.php?topic_id=25966623&page=1
Is anybody on here having the same problems and how could I fix this? The HDD trick doesn’t work for me

http://uk.gamespot.com/pages/forums/show_msgs.php?topic_id=25966623&page=1
Is anybody on here having the same problems and how could I fix this? The HDD trick doesn’t work for me

MS know of the problem as it’s widespread so hopefully they will release a patch soon.