jQuery.param

jQuery.param

I have next code:
    var $checkedRecords = $('input[name="checkedRecords"]:checked');
    var checkedRecords = $checkedRecords.map(function() { return this.value; });
    var data = jQuery.param({ checkedRecords: checkedRecords });

There is error on line 3:
uncaught exception: [Exception... "Not enough arguments" nsresult: "0x80570001 (NS_ERROR_XPC_NOT_ENOUGH_ARGS)" location: "JS frame :: http://localhost:62293/Scripts/jquery-1.5.2.js :: anonymous :: line 6846" data: no]
Seems like $.param iterate via all properties of object, like prevObject etc.

This code did works fine with jQuery 1.4.2. Result was:
checkedRecords[0]=1050&checkedRecords[1]=1052

Any solution?
Thank's