with dmesg posts - and it is best to post them here - it is usual to copy out the bit that seems relevant, with maybe a couple of lines either side so we know where it comes in.
The signal level seems low: -57dBm but -80dBm is usually still high enough and the sensitivity is currently set to -121dBm. This is where I start to suspect something wrong with the hardware.
I notice the access point address is a row of zeros? Is this correct? (Dosn't seem likely. check access point address.)qv. wvconfig man page:
An address equal to 00:00:00:00:00:00 means that the card failed
to associate with an Access Point (most likely a configuration
issue). The Access Point parameter will be shown as Cell in ad-
hoc mode (for obvious reasons), but otherwise works the same.
If /proc/net/wireless exists, iwconfig will also display its content.
Note that those values will depend on the driver and the hardware
specifics, so you need to refer to your driver documentation for proper
interpretation of those values.
... check cat /proc/net/wireless
The mn page has this to say about the signal level:
Received signal strength (RSSI - how strong the received signal
is). May be arbitrary units or dBm, iwconfig uses driver meta
information to interpret the raw value given by /proc/net/wire-
less and display the proper unit or maximum value (using 8 bit
arithmetic). In Ad-Hoc mode, this may be undefined and you
should use iwspy.
... so check iwspy.
further reading: man wireless.