This is a better description for some odd behaviour noted on the mailinglist and described in two tickets #2128 and #1938.
The main issue is that the options passed into the javascript helper methods are treated in various ways. In most cases the correct output is created, especially in the cases where symfony has a different syntax than scriptaculous/prototype:
The ajax request attribute synchronous will be true or false because it is checked if the type is set to the string synchronous. But other parameters are taken from the user input. especially problematic are boolean values.
javascript expects true or false, but the current helper just prints the value. which is using php's mechanics and will print either 1 or nothing at all.
The following patch will convert the type for all potential problematic parameters
