I don't know if this could help you at this stage. I found that the eMMC of my N900 was formatted as vfat rather than ext2. I notice some corruption in it after removing Easy Debian, but I umount && fsck it the problem persist. (I even tried -f option)

Then I remount it and connect to PC with USB as a mass storage, and have Windows performed disk checking (remember to check the full disk scan). In the end it found the lost cluster, fixed it and save it under FOUND.000 (it was in fact a corrupted 2G disk image of Easy Debian).

While it's strange that the Windows disk checking fix the eMMC while fsck couldn't, the problem was solved nevertheless.

This is just my experience and might not applicable to others, but hope this'd help you.