I have good news for you all - I had the same problem, my internal 32GB memory card was corrupted.
i found out that the culprit was the big VFAT data partition, /dev/mmcblk1p1, that usually should be mounted on /home/user/MyDocs, but it wasn't.

I ssh'ed to my N900, tried to mount i manually,

mount /dev/mmcblk1p1 /mnt

but got an error.
After i formatted it with

mkfs.vfat -F 32 /dev/mmcblk1p1

and rebooted, everything was fine again !

Hope it will be as easy as at my place,

cheers varac