I worked out any single instance of document.getElementById("MyID").innerHTML = "A value" in this Javascript World Clock guide causes WordPress Admin not to load completely and breaks various areas of the WordPress admin interface.
I solved it by replacing each instance with jQuery("#MyID").html("A value")) which appears to work fine. What is causing .innerHTML to fail miserably but not JQuery().html()?
This is likely the pertinent part of the jQuery source:
Note that it handles exceptions thrown.
See it for yourself in 1.5.2.