Konqueror does not allow the type of an input to be changed once the element has been created using the DOM's createElement() method. Only inputs of the default type (text) can be created.

This page has an onload handler that reports the result of an attempt to create a hidden input. It works with IE 6.0, Firefox 1.0, and Opera 7.54, but fails with Konqueror 3.3.2.