Seriously check out this site. I have the same board and have found his suggestions quite usefull.
My sound has never cut out completely, but the MCP does get quite hot. I placed a heatsink on mine after I would get some playback issues while overclocking. I haven't had a problem since (well I did have one problem, but it was a user error, rather embarassing).
I've also heard that older version of the nForce driver have a better Soundstorm program as far as setup options are concerned. I believe it was the 3.xx drivers. I was instructed to extract the audioutl folder using winrar and make a shortcut to Sndstorm.exe. and ignore the filesize error message if you get one. However, it did not work for me but it was not what was wrong with my setup. Again, some embarassing user error stuff.