I just got my new N810 today, and I am having the SAME issue. I bought it online as there are no retailers who carry it anywhere within driving distance of me, and I DON'T want to send it back and wait to get a replacement, so if there is a way to fix this I would LOVE to know it. I lost the internal memory as well as the card reader -- and it happened while I was downloading the maps. I had left it downloading, and when I came back, it was frozen. I rebooted, and both the internal and external were gone. I can't connect to my computer either so to get documents and stuff on my N810 I have to email it to myself and get my mail on the N810. And I did reflash and it didn't help at all.