Manage tags with HTMLEditorExtender

Hello,

I have an issue by using the HTMLEditorExtender component.

I'm creating a web form on which I have a textbox, extended with this component. I noted that the HTMLEditorExtender creates a <p> tags to manage a new line or a new paragraph, by using Internet Explorer.

With Chrome or Firefox, there is not any <p> tags added, but only <div> tags.

My trouble is that when I initialize my textbox with some HTML text, the <p> tags are not managed by the HTMLEditorExtender component, and it makes me believe that my textbox has no text inside.

By the way, I tried to modify my CSS to manage display by myself, but it's not working :

p
{
    margin:0;
    padding:0;
    border:none;
    font-family:Verdana; font-size: 12px; color: #707172; text-decoration: none;
}

.ajax__html_editor_extender_texteditor
{
    margin:0;
    padding:0;
    margin-top:0;
    border:none;
    font-family:Verdana; font-size: 12px; color: #707172; text-decoration: none;
}

.ajax__html_editor_extender_texteditor p
{
    padding:0;
}

Is there someone to help me ? Do you have any idea to fix my problem ? 

Thank you in advance.