sending ebooks to windows phone 8
i just got a windows phone - lumia 920 - and i can't for the life of me figure out how to import ebooks from my PC to the kindle app on my phone. calibre detects my phone and has an option to send books to the device, but when i do that the books don't show up in the kindle app (calibre creates a folder on the phone called "books" with the ebooks in it, but this is apparently invisible to the windows phone). my previous phone was the droidX and i could navigate to the kindle folder and drag+drop ebooks via windows explorer. with the lumia, i can't find the ebook folder anywhere. i've even tried downloading an ebook in the kindle app (and i'm able to read it like normal), but it's nowhere to be found when i try looking for it in windows explorer.
anyone else have a windows phone, or any ideas?