html table cells aren't uniform width in FF, fine in Chrome and IE8

Question

I'm working on an app in ASP.NET MVC 2, and the output of the table looks the way I'd expect in Chrome and IE8:

but this is how it looks in FF 3.6.8 it looks like this:

I'm using javascript/jquery to add rows, this is the code:

        function onAddItem() {
        itemCount = itemCount + 1;
        var rowString = "<tr id=" + itemCount + ">";
        rowString = rowString + "<td>" + document.getElementById("Order_productcode").value + "</td>";
        rowString = rowString + "<td>" + document.getElementById("Order_productsku").value + "</td>";
        rowString = rowString + "<td>" + document.getElementById("Order_productdesc").value + "</td>";
        rowString = rowString + "<td align=\"right\">" + document.getElementById("ItemQuantity").value + "</td>";
        rowString = rowString + "<td>" + document.getElementById("Order_productweight").value + "</td>";
        rowString = rowString + "<td>" + document.getElementById("Order_productcost").value + "</td>";
        rowString = rowString + "</tr>";
        $row = $(rowString);
        $row.hide().fadeIn("slow").appendTo("#orderedItems table tbody");
    }

Looking in Firebug, I found the row that gets created looks like this:

 <tr style="display: block;" id="1"><td>EC5931A-Tote</td><td>100002</td><td></td><td align="right"></td><td>0</td><td>33250.00</td></tr></tbody>

that is, it adds 'style="display: block;", which seems to be the problem (when I edited it out in Firebug, it looked correct, i.e., like in IE and Chrome). Why is FF doing that, and how can I make it stop?

TIA

EDIT: I removed the .hide().fadeIn("slow") and now it's working correctly in FF. Seems to be a bug in jquery with firefox, altho I didn't see it on the jquery site.