I got the feeling that this was the result of bad knowledge browser-behaviour, HTTP and HTML and JavaScript. I still have no idea why the form isn't just submitted as is, using the name and value of the submit to determine which button was clicked.
In addition, the JavaScript could be reduced. "if(typeof window.clearFormHiddenParams_Blah!='undefined')" can be written as "if( window.clearFormHiddenParams_Bla)". Considering that the code is repeated all over the place, that can make quite a difference.
