I am using the evaluation of the editor and it seems that whenever the editor is blank, when you try to switch views it keeps loading. This problem seems to be only on firefox. To be more specific whenever the editor is blank(no HTML at all), switch from normal mode to preview, then switch from preview to normal mode and the browser does not stop loading. Remember this problem only persists in firefox. I have also reproduced the problem here http://cutesoft.net/example/general.aspx. Interestingly enough when you click on HTML mode the browse stops loading however I am sure this will cause a problem nonetheless. After the problem happens one time it will keep happening regardless if the editor contains HTML or not.

 

Thanks You