firefox header problem

Just upgraded to 2.1 and am having a frustrating time.

Richtext editor won’t work in my usual browser Safari.
It will work in Firefox (although I still haven’t figured out how to get it to do hyperlinks).

However, Firefox (latest version)has completely removed my header making my blog look very strange indeed. The header is there in Safari, not there in Firefox. Does anyone have any suggestions?

https://www.fefihohum.com