h1, h2, h3, etc problems with % font sizes?

Hi, I am using an external style sheet, defined by using

$oFCKeditor->Config['EditorAreaCSS'] = '../../mystyle.css' ;

At first I thought it wasn't working, because my h1, h2, etc tags were coming out huge. I am required to use percent font sizes, and they are appearing in the FCKEditor frame larger as when not in the edit frame.

Is there a problem with FCKEditor when using percent % font sizes? Please help if you know how to work around this.

Thanks,
Geoff

V 2.6
Win, IE7