I have been using glabels (version 1.91.1) to print business cards, and I find that it's much easier than having to load Open Office to do so.
However, I cannot get properly aligned prints on *round* CD labels.
The paper stock which I use is Fellowes NEATO (Product Code 853600).
Are you sure all settings are "letter"; i.e., that neither the app or the printer are set to something like A4?
Gerry Tool