Dave,

There are several things folks have done to correct this, but for me the fix was to go into the FSX folder under sounds and mark the "DON'T_SINK" sound to .old - end of problem. This is not a correct fix since all you are doing is getting rid of that warning, but it does the trick for me. The don't sink call out is a takeoff warning only and you should never get this during landing.

Lou