Ok, I've got a weird one. My tablet's been unexplainably crashing, locking up, etc, etc lately. But only after I've been out doing something on the secondary flash card. So after crashing several times in a row, I went to see what was causing all the fuss. I opened the file manager and only the main drive was still there. The internal and external MMC cards were gone. IE, I got the same screen as when I would connect the tablet via usb.

So ok, I reboot, nada. I then shut down, pull the external card, reboot. BAM! Everything's back and the tablet's happy. Stick the external card in, it won't see it. I do everything like I normally do. Nothing. So I'm thinking bad adapter. Swap adapters. Nothing. So I try a new card. It works on the first try. So I rule out bad adapter. I put in the old one, nothing.

I tried the old one on my PC, and it works fine. Even copied stuff off the old card to the new one. So far all is good. I even did a scandisk on the internal card. It took a bit to complete, but it didn't throw any errors, so I'm not sure what to think there. Anyone got any ideas? Obviously the old card is still good, and yet the tablet won't see it. I'm really baffled.

It could be that the card is dying, it seems to happen to my A-Data cards alot (thank god for a life time warranty).

Hmm, that's interesting that you mention a-data. Because that's exactly what the card is. Well then, I guess I'll be RMA'ing that sucker then. Although, if it's really dying, I should likely fully kill it first to guarantee an RMA. Of course, if they take them on RMA without question, then that's a different story entirely.

What happened on my last card and (this one but i don't mind it right now) is that it lost some GBs. This time it was 3-4 Gbs so it reads 11-12 when it should be 15 for a 16 GB card. But they accepted it, just inform them what the issue is.

I had almost exactly the same issues, my internal 4gb SD kept randomly disappearing and my n800 rebooting. I was downloading a lot of podcasts to this card most every day, which I suspect was the cause of it's failure. Touch wood, since replacing the card with a new one, my n800 has been rock solid.

Yeah, mine's a ton more stable now and hasn't complained at all. Guess I'll get the other one RMA'ed. Now I just gotta figure out how.