It's because you didn't set Edit tab to true, there are a few events cannot be hooked in code view.

 

Here is a work around.

 

Create a new style sheet, name it P.css.

 

Copy/paste the following code into it:

p { margin:0px;}

Then use EditorWysiwygModeCss property to let cute Editor use this style sheet:

<CE:Editor id="Editor1" EditorWysiwygModeCss="p.css" runat="server" ></CE:Editor>

Hope it helps.