I have a form that contains a dynamic drop down. The content of drop down 2 is dynamic depending on the selection on dropdown 1. Pretty standard stuff. I hook a function to dropdown1's change event, and load, using ajax/json, the dropdown2 with data retrieved from the server. I use the pretty simple lines of jquery code:

    $("#id_select1").empty;
    var e = document.createElement('option');
    e.text = "orange";
    e.value = "1";
    $("#id_select1").append(e);

This works in firefox, but not in IE. Turned out this is a known problem and it is marked "wontfix". You can read the bug report here. This is the work around:

    $("#id_select1").empty;
    $("#id_select1").append("<option>Orange</option>");

Not very nice, but at least it works.