by Albert Wiersch » Tue Dec 01, 2009 9:46 am
I wonder if this could be an issue with "compatibility view". Perhaps one is showing it in compatibility view and another isn't. CSE HTML Validator doesn't let you directly change the compatibility view settings, but you may be able to change them in IE and the "Compatibility View Settings" may affect how CSE HTML Validator previews the file.
It might also be the text size causing the difference. CSE HTML Validator doesn't currently let you change this in the viewer. I will have to look into it for a future version.
If this doesn't answer your question, I'd be interested in seeing a screen shots showing the difference.

Albert Wiersch