Indeed, curious you should mention Paint Shop Pro. I design/edit virtually all of my labels in PSP, however I still prefer to print them from within SureThing because of the aforementioned alignment issues. For simple to moderate layouts, the editing abilities of SureThing are very good, but when it comes to layering, transparency layers, etc., there's just no match for a true image editor. When finished with the design, simply save it as a high-quality JPG and insert it into Surething and print.
Best regards,
Floyd