DP v 5.7.1904, FF3.0.14, IE 8.0.6001, using DayPilot Month

I'm trying to override the context menu on specific events in DayPilot Month. I've tried using the following, but it results in no DayPilot menu (and a browsercontext menu).

protected void DayPilotMonth1_BeforeEventRender(object sender, DayPilot.Web.Ui.Events.Month.BeforeEventRenderEventArgs e)
{
e.ContextMenuClientName = "emptyMenu";
}

<DayPilot:DayPilotMenu ID="emptyMenu" runat="server">
<DayPilot:MenuItem Text="You may not edit this event" Action="PostBack" Command="noEvent"></DayPilot:MenuItem>
</DayPilot:DayPilotMenu>

The "noEvent" command is properly handled in DPMonth_EventMenuClick.

Suggestions?

Thanks!