After diving into the cache control and figuring out that is not the right way (it clears previously filled form items) I've chosen the different approach:
- $(document).ready(function(){
- $('#submit').removeAttr('disabled');
Just after the 'document ready' event I've inserted an attribute removing code and it works. What a simple way! Please let me know if there is any potential risk (this attribute is not present in a fresh (just loaded) document).