I use the same UI as you and have no issue with Tracker. I have pieced a custom UI together for myself. I take a little from here and there and tweak it. You need to make sure that u apply the tracker definition with in the existing UI and make sure all tags are closed. I use this XML Maker and have had no issue. It will let you know that you have made a mistake or if the string is bad. You can download it here
http://symbolclick.com/. Let me know If you can't get it to work. and I'll see what I can do for you.