Placing a backorder does not guarantee that you'll get the backorder. In MOST cases you will never see the name you backorder through them... unless it's something without linkpop, or an ovt score. On the upside... you can use the same backorder to try and grab another domain... and so on until you are successful. Just click the change link and enter a new domain to backorder.
If you get an error when trying, that means someone else already had a backorder on that name through GoDaddy...
I hope I understood your issue correctly... and that this helps.
Good Luck
Jennifer