[jQuery] $().each() only iterates through first item

[sydneyos]

I have the following expression where is_preferred_email is a class
assigned to three elements in my page:

        $j(".is_preferred_email").each(
            function(i) {
                this[i].checked = false;
            }
        );

if I put "alert(this[i].name);" in the function, I only ever get one
message, which is consistent w/ the checking/unchecking behavior I
see.

Likewise, a call to $j(".is_preferred_email").size() returns 1.

alert(j$("is_preferred_email")) gives me

[object HtmlInputElement],[object HtmlInputElement],[object
HtmlInputElement]

so clearly it is finding all three items.

I'm stumped.

I am also using prototype but have called var $j =
jQuery.noConflict();

I'm sure I'm missing something obvious - hope someone can pick it out.

Thanks,