I use Firefox and Explorer, and in both browsers it seems like the appearence in the Page Body field in the WYSIWYG is different from the one in the webshop or homepage. For example, many times the text in the WYSIWYG is centered as default, but is not in the user end. Or if you place an image beside the text in the WYSIWYG, it shows up above the text in the webpage.
Is it just me, or do you experience this problem?

I use several browsers and never notice any real difference
 
Chris

We haven't noticed a difference either. The problems you see are probably caused by CSS on your main pages.

I notice differences sometimes. I've certainly learned that it's best to avoid complicated tables or formatting. For instance if you create something complicated in FrontPage (outdated but widely used) it may not show up right in one of the popular browsers. When any page gets too screwy, I just copy everything to Notepad to strip away the formatting and start over. It takes less time in the long run.