Remove all jQuery code and insert this code, the same thing happens in IE--the text field does not change to a button.

window.onload = function() {
 document.getElementsByTagName('input')[0].type = 'button';
 document.getElementsByTagName('input')[0].value = 'Click Me';
};

In the past, were you able to get IE to change text fields to buttons, or is this something you are trying for the first time? The Microsoft documentation for input[@type=text] says this: "As of Microsoft Internet Explorer 5, the type property is read/write-once, but only when an input element is created with the createElement method and before it is added to the document."

http://msdn.microsoft.com/library/default.asp?url=/workshop/author/dhtml/reference/objects/input.asp