from what I've learned and to ensure cross browser compatibility I advise:
1 - remove any comment from code (e.g // <!-- etc...) that goes into the HTML WYSIWIG editor as it can screw things up and does!
2 - when entering flash related code ensure that u use "true" instead of "-1" and "false" instead of "0" in the PARAMS. (caused issues with safari playing flash in custom blocks/pages)
3. better off editing in notepad and pasting into the WYSIWIG editor as Frontpage & Dreamweaver can add code unecessarily
4. WYSIWIG editor looks different in all the different browsers so stick with IE I reckon (well for me anyway)
5. filepaths are relative to the root for all code entered in the editor. e.g [root/]images/mypic.jpg
