I have some simple processing going on inside a RadAjaxPanel, but when I add the RadAjaxLoadingPanel to get the spinner, the whole Panel just turns white / disappears until the postback returns. 

This is a SharePoint Visual webpart and is now happening in two different projects (different site collections), regardless of what controls are inside the RadAjaxPanel.

I actually solved this by putting a 'Skin' attribute on the Loading Panel. However, now the page postsback on the initial click and Ajax every other click. Why isn't ajax working on my first postback?

Hi Michael,

I am glad that you have found out how to show the RadAjaxLoadingPanel. 

For your other issue, please refer to this forum thread on the same matter and see if it works for your scenario: "RadAjaxPanel cauing full postback 1st time".

Hope that helps.

 
Regards,
Konstantin Dikov
Telerik