Problem with live mouseover

Problem with live mouseover

Hi I'm currently using the tooltip plugin to display an image preview on mouse over, this is the function that im using:

$('.preview_boton_mercancia').live('mouseover', function() { // image which will display the tooltip on mouseover.
        var id = $(this).attr("id").split("_"); // splits the id of the image. ex. id="image_21"
        var id_mercancia = id[1]; // gets the id of the image I need. ex. id_mercancia = 21
        $('#preview_'+id_mercancia).tooltip('#img_'+id_mercancia); // displays the thumbnail of the image on the tooltip
});

The problem is that it doesnt work on the first mouseover, after I hover the mouse the first time over the icon THEN it works as intended, I dont know if I'm not using the live function correctly or if its a problem with the plugin ??

Does anyone knows what the problem might be? Thanks in advance!

PD: I think the problem has something to do with that I'm just "binding" the event but not actually "calling" it on the mouseover?

PD 2: I just found out that the live function isn't working on newly created elements at all. Just works as described on the elements created when the page first loads.