Please Note: This is a solution rather than a question.

On the following example:

http://www.telerik.com/DEMOS/ASPNET/Prometheus/Dock/Examples/MyPortal/DefaultCS.aspx

The following javascript error throws if you are using master pages:

Microsoft JScript runtime error: 'null' is null or not an object.

This is caused by the following line:

ScriptManager.RegisterStartupScript(dock, Me.[GetType](), "AddDock", String.Format("function _addDock() {{" & Chr(13) & "" & Chr(10) & "" & Chr(9) & "Sys.Application.remove_load(_addDock);" & Chr(13) & "" & Chr(10) & "" & Chr(9) & "$find('{1}').dock($find('{0}'));" & Chr(13) & "" & Chr(10) & "" & Chr(9) & "$find('{0}').doPostBack('DockPositionChanged');" & Chr(13) & "" & Chr(10) & "}};" & Chr(13) & "" & Chr(10) & "Sys.Application.add_load(_addDock);", dock.ClientID, DropDownZone.SelectedValue), True)

DropDownZone.SelectedValue is referenced which will return RadDockZone1 instead of the required RadDockZone1.ClientID.

There are a few solutions to this problem but i found the best one was to populate the Rad Dock selector at runtime.

Simply add the following code to the page load:

If a better solution is avalible please post it here.

 <div id="rightContentDiv" class="rightContenDiv">
      <div class="pageContent" >
           <telerik:RadHtmlField DisplayHeight="200px" 
            DisplayWidth="100%" FieldName="PageContent2" 
            runat="server" id="RichHtmlField1" >
           </telerik:RadHtmlField>
      </div>
 </div>

 
.rightContenDiv
{
 float:right;
 width:259px;
}

.pageContent
{
      font-family:tahoma; 
      font-size:10pt; 
      color:#5B5B5B; 
}

Thanks
Mark