Hi there,
I'm going to suggest one thing, based on what I could translate from german.
Looks like you have permission issues changing from one firmware to another, right?
If that's the issue, are you now with Alt-F or the original firmware?
I had the same issue with the change to Alt-F. But on the web interface, there's one option (I could not remember on the top of my head now, I can check later), that you can define permissions to the folders. Since I'm not going to define different permissions, I set all /mnt to "nobody,nobody", and everything was fine.
If its the other way around (Alt-F to Dlink), I believe the only way to change all permissions will be to "root" it (using ffp, for example), and in the telnet session, do something like this:
chown nobody,nobody * -R
[]´s
Paulo