scrolling problem with mozilla.

Question

i have developed a web page using silverlight 4.0 .but im unable to view the whole page in mozilla.only half of the page appears there.i tried to add a scrollviewer to navigation pages.but still not working.do i need to set any browser settings ? or seeting with border/grid/frame ?
when i installed visual studio,i set mozilla as a default browser.now i want to change into internet explorer. how to change?

Thanks