[SCION]

OK, I enabled the stock reader (disabled by renaming reader.apk to reader.bak). I switched between two books to see if the bookmark held. Initially it did, but after the third try one book returned to the cover.

I do recall that a handful of people mentioned that sometimes the book opens to the cover, not the last page read. I would say you're not alone with this every now and then fluke. I guess we could assume it will be corrected with an update. It's up to you if you want to keep the NOOKcolor or purchase something else.

If your intent is to root anyway and use an ereader app, perhaps you can overlook this. You said you wanted to make use of your calibre tags. You won't be able to do that with the stock library.