Raymond says that dialog boxes are not the place for logic puzzles.

I ran across a configuration dialog box that had the item "Turn off Feature X". This is a negative-sense checkbox, which turns your dialog box into a logic puzzle. Checkboxes should be phrased positively. "Use Feature X". (The only exception to the "no negative checkboxes" rule is the "don't show me this message again" checkbox.)

Negative-sense checkboxes turn into a game of confuse-the-user. "If I uncheck 'Turn off Feature X', then I'm not not running it."

It gives the impression that your program is trying to sneak something past the user the same way malware does, or the same way eight-year-olds do when they're trying to bamboozle their parents.

"Can I not not not not not not not go to Jimmy's house?"

It is a simple thing but can really save your users from time and frustration trying to decipher your language.