I was actually just messing with the Zune eReader the other day. I think the original FeedBook catalog may have changed or updated because no matter how times I tried I'd just get that error message. I even tried other catalogs, to no avail. Runewake2's right, the readers from here are the better choice. I recommend "
Book Reader" by amertak or "
E-Book Reader" by kirarulzz.