I took a pdf and loaded it into Calibre. I then converted it to pdb. Last I uploaded it to my nook. All that went fine.

When I try to open the book on the nook, the typical DRM screen appears asking for my name and credit card number. But there should not be any DRM on the file.

Is this a nook problem? Or does Calibre add DRM? I looked for some default DRM keys that it might add but could not find anything.

If its a nook problem, I'll go post on their forum. The reason I tried it is I'm trying various formats with this big ugly pdf I have for html5 and so far, on the nook, no matter what format I pick, it is not very useful.