I want to disagree in the case of N800... I thought too that the corruption was due to removal of SD card etc in the first couple occurences that happened. But when the 2GB card corrupted and became not recoverable it was inside (internal slot) N800 and I was using Maemo Mapper. All of a sudden the Mapper started to complain file not found or similar... Before trying to remove and replace the card I tried to look for the memory card content using the N800 file manager and it showed the memory card as grayed out... so it wasn't recognized by the N800. After that I tried to remove and reinstall the card and I have not been able to do anything with that card since then.

Same problem here, and also with Maemo Mapper. So, now I don't want to use maemo mapper until somebody fixes that problem. The memory card slot is the external, and it's a 2GB transcend.

These reformatters were probably written before Vista, so I'd want to try one under XP before I concluded it didn't work. My sd card became unusable while on the vine, not after being removed. It could have to do with Maemo Mapper, which in general seems well-behaved to me. I will keep using Maemo Mapper and see what happens.

Are all of these problems with SD cards (as opposed to MMC cards)?

Also, to anyone for whom their cards died while Maemo Mapper was running: what brand of SD card are you using? Transcend?

My 2GB SD card was a cheap Topram brand from eBay... thus it "could" have died just because of its "quality", or lack of...

I don't think Maemo Mapper is the reason for these issues, other than it probably gives a good workout for the File System due to frequent reads/writes. I believe the N800 kernel has some bugs/issues that cause these corruption problems.

As I said before have experienced these file system corruptions on N800 with 1GB MMC card, 2GB SD card and with 4GB SD card.

I agree. It seems like something in the N800 file system code breaks down when it is worked too much? A threading or permissions issue maybe?

My (fixed) problem was with a 4gb Transcend sd card.

Probably because the tablet was shutdown without the card being unmounted (meaning a freeze or crash that forced you to remove the battery). The kernel being used by the tablet is a stable kernel - if there was an issue, it would have been found long before it made it to the N800.

When it goes read-only, it means the filesystem has been damaged in some way. I doubt that mapper caused it itself. You can just unmount the card, pop it into a Windows computer and run scandisk on it or fsck.vfat on the card in Linux. It'll be fixed and will return to working normally.

I've been having lots of problems with my SD cards as well - particularly in the "removable" slot. It seems to happen when particular applications either break/die/loop or something.

Many times the card will go to pot and not be able to restore it properly - I can run scandisk on it and it doesn't find any problems, format it, etc - then magically the card starts working and all the files are there. Very strange. Almost as if one of the File Allocation Tables gets corrupted but something in a Windows machine will fix it silently.

It's getting very frustrating though as it appears to happen all the time lately.

Any thoughts on just formatting to ext3 or something rather than FAT/FAT32?

Seems like there are tools available to fix ext2/3 filesystems but no fsck.vfat. Very strange.

I realize that I wouldn't be able to mount the card in windows when plugged in through USB - but don't have a big issue with that.

i have had a kingston mmc card work for a little while and then go strange.

i assume that it arrived faulty but it took a while to notice.

now when ever i buy a memory card or usb drive, i test it first. a simple method i use is to copy a bunch of ubuntu isos onto it and md5sum them. then if i can be bothered leave them for a day and md5sum them again. i have never had a problem with a card that has survived that.