I'm not sure, but it seems that the solution here is to decide which font group you wish to adjust and change the related CSS accordingly.
Sometimes a plugin is installed or even deactivated that has mildly conflicting CSS with sections and the change can alter the appearance of your site. The easier solution is to simply adjust the CSS, which is what James is trying to help you do. If you'd prefer to leave the blockquote alone, then the alternate option is to change the content font size. You can use Firebug to locate that, fairly easily and test adjustments before implementing.
Once changed, your site will look exactly as you'd like it to, which is a goal we share with you.