a friend of mine has the same problem like many other users with Ubuntu Precise. With Ubuntu 12.04 wireless is dropping sometimes. He has to reconnect to the wifi SSID.
This is the relevant output of such a drop: http://fixee.org/paste/8hwpt89/
Would be nice to get help if someone knows why this occurs.
Info The network hardware is the following: http://fixee.org/paste/tu9x728/
I post this as links to keep the question short and clean
Update 2nd of May
Here you have more
dmesg informations: http://fixee.org/paste/tkv95th/