Typos are often te worst bugs to find ;) and IE can be very stern about it.
I added a missing semicolon (;) and removed a unneeded comma (,)
Before:
var opener = $('box2');
var boxtoopen = $('box');
var testmorph = $('test')
boxtoopen.set('morph', {
duration: 800,
});
After:
var opener = $('box2');
var boxtoopen = $('box');
var testmorph = $('test');
boxtoopen.set('morph', {
duration: 800
});