Hello,
        I have been running into this problem for a while now. Whenever I try to use the text/html module in Firefox there is always a gap at the top of the page. I do not run into this gap issue in other modules. I have tried multiple css styles to fix this to no avail. I have found numerous articles about this problem stating that in between tags there is a blank line. In order to attempt to fix this I have placed overflow: hidden; in my CSS. However, every fix suggested has failed when attempted. 

        To be more specific, between the title bar and the content there is always what seems to be a padding. Using a negative margin-top does nothing to resolve the issue. The pane is in a TD tag where all padding, spacing and borders have been set to "0". I have also set the valign="top" just in case. I have tried setting display:block;. I still end up with a 4-6 pixel gap between the title bar and the content. An example picture of what is happening can be found here.

        If someone can give me guidance into this problem I would greatly appreciate it.

Sincerely,
Benjamin J W D

That's the way Firefox displays P tags... such a pain when trying to make content match IE

When you're back in the editor, check the Source view and remove the P tags from around the content.

You can do other more permanent things such as specify a fixed padding-top:0 for paragraphs in your css file, or go into the FCK editor's custom config js file and change the default tag to div - you'll see it commented in there somewhere. I use both the zero top padding and divs.

Regards,
Rob

Why people want to blame the poor P tag?, the P tag is the standar way to manage paragraphs. Be sure to add the correct style behavior in your CSS styles and that is it.

I will never suggest removing the P tag as a soluion.