With a little more experimentation I found the solution to stop the encoding. Web/CientScript/mojofckconfig.js
Change this to false:
FCKConfig.ProcessHTMLEntities = false ;
Clear your broswer cache, then try the editor again.
Unforunately the only way to fix the existing content is to enter it again.
I will make the same change here so it will be fixed in the next release of mojoPortal.