So it's not lack of space, there's still 7.9MB avaialble.
Did you restore a backup after you've flashed? It could also be you've backupped stuff you shouldn't, like /etc/pam.d. If you restore that from a previous version, it might have broken authentication.
I install fresh soft from usb, everythink works fine. Then i chek for updates , in update section i';ve got 104 updates. After instaling them all , i lost ftp connection .