Reflash with USB fails

hi everybody

i have a problem with reflashing my mr3020 and was advised in the chat to search help in here.
i do all the steps like described under [piratebox.cc]
in the chat i was also told to try then the steps as described in [piratebox.cc] under "Update Piratebox".
the problem there is, i have NO directory /mnt/usb. also, when i followed the reflash-explanations, i had to put sda instead of sda1.
here's some output that might help:

Language: PHP
root@OpenWrt:/# df -h
Filesystem                Size      Used Available Use% Mounted on
rootfs                  896.0K    208.0K    688.0K  23% /
/dev/root                 2.0M      2.0M         0 100% /rom
tmpfs                    14.2M     68.0K     14.2M   0% /tmp
tmpfs                   512.0K         0    512.0K   0% /dev
root                     14.2M     36.0K     14.2M   0% /tmp/root
overlayfs:/tmp/root      14.2M     36.0K     14.2M   0% /tmp/root
/dev/mtdblock3          896.0K    208.0K    688.0K  23% /overlay
overlayfs:/overlay      896.0K    208.0K    688.0K  23% /

seems there is no usb-stick.
so advised in the chat, i tried again to reflash. but same story...
somebody got an idea? any help would be great. if you need more information, just let me know!

edit:
i tried with another usb-stick which was recongized under sda1. then i could fullfill the steps needed to upgrade the piratebox. but still, i can't connect to SSID “PirateBox: Share freely” as it doesn't show up in available networks.

edit:
in /etc/config/wireless there should be a line "option disabled '0'". if it's "option disabled'1'", it won't work, just pu an 0 instead a 1 or put a # at the beginning of the line.
after i did this, the Piratebox-ssid showed up and i could fullfill the post-installation steps without any problem.