I'm running Ubuntu 12.04 (with all drivers updated).
I'm connected to my wireless router, everything works well, but after 10 minutes using Firefox / Chrome / Skype / transmission the connection is lost only on Ubuntu. Other devices still have a connection to the Internet.
Ubuntu is still connected to the router but no access to internet, even the router address is not accessible.
I have to disconnect and connect the Wi-Fi to establish a new connection.