Hi trisha33,

I had the same problem! but i found a solution!
find the js file jscript_a-mootools.js in \includes\modules\pages\checkout_shipping
and add the following "jQuery.noConflict();" on the top of the file underneath the remark //MooTools and above the var MooTools like this

//MooTools etc..

jQuery.noConflict();

var MooTools={ver....

this should do the trick! for me it works!
why is this, because of a conflict in jquery..