DOM Changes Won't Display

I have a table in IE 6.0 listing several items where clicking on a row will bring up another window showing details for that item. Clicking a particular button on the detail window will change how that item appears on the initial list screen by altering it's background color, class name, and default cursor.

The problem I'm having is this -- sometimes it works and sometimes it
doesn't.

There doesn't appear to be any rhyme or reason as to when it works and when it doesn't. Below is a code snippet showing how I'm going about making these changes. Any input would be appreciated.

trNode.className = "approved";
trNode.style.backgroundColor = approvedColor;
trNode.style.cursor = "default";