Form Will not Submit after RadConfirm in Firefox
After showing a RadConfirm dialog, the form will not submit in FireFox when
form.submit() is called or the
.click() method of a RadButton does not initiate the postback as expected. This also applies for RadAlert and RadPrompt.
Avoid using form.submit() and initiate the postback from a button. You can find examples in the Button - Confirm Postback (see the RadConfirm function in scripts.js) and Window - Confirm Dialog Integration live demos. If the form submission was not initiated by a button click, you can add a button that you can hide with CSS.
You can also try using the Classic RenderMode of the RadWindowManager because it does not use <button> elements but <a> elements to generate the buttons in the RadAlert/RadConfirm.