I was wondering if anyone could offer some advise on an issue I have encountered while using the Telerik RadDatePicker control with the dnn wrapper (dnnDatePicker).

I am currently developing a module that will allow users to enter lots of dates, hence the use of the date picker. I have noticed that having lots of these controls on my page adds a huge overhead and the page load time (during postbacks) is getting unworkable (about 8 seconds). The solution I thought was to add a RadCalendar (DnnCalendar) control to the page and set the SharedCalendarID for all of my date picker controls. This should render a single calendar, shared by the date pickers rather than a separate calendar for each control.

However, I encounter an error when doing this:
Could not find a RadCalendar control with ID of 'calDatePicker'. 
Use the SharedCalendar property to pass a direct reference in your code-behind if the control is not in the current naming container.

I suspect the problem is down to the dnn wrapper. Anyone got any thoughts or advise?