Single quotes not being replaced.

In the fckeditor.js file is a section of code that replaces certain characters.

text = text.replace(/&/g, "&") ;
text = text.replace(/"/g, """) ;
text = text.replace(/</g, "&lt;") ;
text = text.replace(/>/g, "&gt;") ;
text = text.replace(/'/g, "&#39;") ;

All of these are working properly except the last one... when I type in all of these characters and then click the 'source' button the first four have been replaced properly... but the last one, which is the most important to me as it will break queries is not getting replaced.

Is there something I need to change/add to get this to work properly?