The get_text() client side function of the editor seems to append a newline character to the retrieved text. This had the effect of breaking a string comparison I had to clear placeholder text ('enter detailed text here') when the user clicks on the content area. The problem is apparent only on Chrome and Safari, but not IE.

I fixed this problem by removing the trailing newline character using a regular expression:

var t = editor.get_text();
t = t.replace(/\n/g, "")
....then do the string comparison

The problem appeared in version 2012.2 912.

A possible workaround: take the PageProperties.ascx dialog and use it as an external dialog in your project and change the _setClass: function to

_setClass: function (element, cssClassHolder) { element.className = cssClassHolder.get_value(); } 

When paragraphs are pasted from e.g., MS Word, multiple BR tags are pasted instead of the corresponding amount needed.

The flowing custom handler shows how this can be handled as per to the specific requirements:

<telerik:RadEditor runat="server" ID="RadEditor1"
    OnClientPasteHtml="OnClientPasteHtml"
    StripFormattingOptions="AllExceptNewLines">
</telerik:RadEditor>

<script type="text/javascript">
    function OnClientPasteHtml(editor, args) {
        var commandName = args.get_commandName();
        var contentToPaste = args.get_value();

        if (commandName === "Paste") {
            contentToPaste = contentToPaste.replace(/(<br\/>)+/gi, "<br/>");

            args.set_value(contentToPaste);
        }
    }
</script>