trouble reading kindle book converted to epub Nook chokes

[Dob43]

Ok I hope this is the right location. Here is the situation I have a kindle book I bought and I am trying to convert it to read on my Nook. I am using Calibre and after conversion to epub it reads (and looks great) on everything I throw at it including Calibre, FB reader, ADE, among others. However when I put it on my Nook it asks for my name and credit card to unlock the book. Considering it is not encrypted this was a bit of a shock. I looked around in the epub files and in the meta-inf folder I found a encryption.xml which I thought was odd. I removed it but then the Nook says error: sorry can't open the book. This happens with both Nook tablet and Nook HD.

I did some digging and apparently if the book is created with AdobeinDesign and fonts are embedded (which is done by default) it adds a encryption.xml file. But I know deleting that didn't do it so I went looking and in the end I did:
–encryption.xml from meta-inf folder
–Removed the fonts from the fonts folder (there were two 00001.otf and 00002.otf)
–removed these lines from page_styles.ccs:
@font-face {
font-family: “OPTIUnivers57_Rom”;
src: url(../Fonts/00001.otf)
}
@font-face {
font-family: “OPTIUnivers67_Bold”;
src: url(../Fonts/00002.otf)
}
–Removeed lines from stylesheet,ccs
font-family: “OPTIUnivers57_Rom”, “Helvetica”, “HelveticaNeue”, sans-serif;
background-image: url(../Images/00005.jpeg);
background-position: center top;
background-repeat: no-repeat;
font-size: 1.5em;
font-style: normal;
font-weight: bold;

But the daft thing still wouldn't open (Error sorry can't open book). So I went and deleted all extra pages (author bio, table of contents page, extra images) leaving only cover image, the page break image (both jpg) and the text. Deleted all references to deleted images (removed from the images folder as well). The book still won't open. I even tried converting the original file to mobi then epub, I still get the can't open book error. But no asking for decryption key so at least it gets rid of the fonts and encryption.xml file.

Anyone have any other ideas? If I convert from the kindle book to a PDF, the Nook will open it no problem. So it must be choking on the formating somewhere but I have no idea what.

[kovidgoyal]

The Nook has easily the worst of epub support. Unfortunately, there is no way to know exactly what is tripping it up other than trial and error. Look for unusual markup like tables/forms/frames. Delete all the css.

[Dob43]

Ah ok, thanks for the input. Hmm I deleted all the .css files, the image files that were associated with it, and I still get the error. I don't see any unusual markup like frames/tables/forms. It is a fiction novel and doesn't have odd formating that I see. Frontmatter, table of contents with links (very simple), the chapters, about the author, her other books, back cover.

I was hoping that someone might have ran into this before. In the past I have thrown a LOT of epub books over the years and this is the first one my Nook choked on. I guess I will keep deleting and see if I can find it. If not then PDF is a easy way around it. Or I can rebuild the book copying the data over without any extra formatting (although since convert to PDF works, doubt I will bother). Another option is to use FBreader instead of the built in reader app (although I would still like to figure out what the problem is if possible).

Any other suggestions are appreciated.