The .bind() and .one() methods take two or three arguments, and have the signatures:

bind(type, data, handler)

bind(type, handler)

Currently, jQuery 1.4.2 distinguishes these cases with this code:

if ( jQuery.isFunction( data ) ) {

fn = data;

data = undefined;

}

This means that if you pass a function as the data argument, it will be treated as the handler argument and the handler will be ignored.

I propose that you change the code to instead test like this:

if (arguments.length === 2) {

fn = data;

data = undefined;

}