>>Javascript fails when a Master Page is added to this page. Is there any workaround?
>
>I'm not sure you have the same problem as me, but try Re: Setting focus to the control on the page (AJAX site) Thread #1294462 Message #1296101

In this case FocusedControl is a property of the base page in Mere Mortals. I don't know the answer, but you could probably add the MM debug references to your project and set a breakpoint in your code.
Tim