jQuery Grid Plugin - jqGrid

I'm struggling to insert elements into jqgrid cells using jquery or javascript--I get "object Object" appearing in the jqgrid cell, instead of the <span> object I should be seeing, even though my syntax seems to be correct.  

I'm using logic I found in this forum on a slightly different question, with an answer posted by Tony--it had to do with how to find the TD element and bind a click function to it.  I'm using the same logic, but instead of binding a click function, I'm trying to append a DOM object to the TD.  This syntax works fine when I'm appending simple html content--but not when I'm appending an object (span, div, img, etc.).  Does it have to do with the sequence in which the DOM is initialized?

The code is:  (using version 3.7.2 and XML)

afterInsertRow: function (rowid, data) {

var objSpan = document.createElement("span");

var txtSpan = document.createTextNode("hi, I am some text");

objSpan.appendChild(txtSpan);

$("td:eq(0)","#"+rowid).append(objSpan);

}

Instead of seeing "hi, I am some text" rendered in span tags by the browser, I'm seeing "object Object."  

Suggestions?