Many of the settings under Tools -> Options -> Text Editor-> C/C++ ->Advanced are of the form "Disable something".
It'd be much more logical if they were "Enable something"!
Here's a comment from http://blogs.msdn.com/vcblog/archive/2009/11/17/improvements-to-find-all-references-in-visual-studio-2010.aspx which sums up the situation:
"Some remarks on the settings shown in Figure 9:
Why are you provoking double negation in the settings? I have to set Hide Confirmation to false to see everything and true to get a reduced view. This seems to be counter-intuitive. This is similar for all settings on this page: entering true to reduce functionality and false to extend functionality. You always have to look twice and think about.
Just a usability issue but it is so ubiquitous.