alfter the upgrade of ubuntu from 10.10 to 11.04 beta my network card is a bit unstable.
The driver ath5k i correctly mounted into the kernel, the interface i properly detected (and showed in iwconfig list) and the network card is up.
The main problem is at the startup and resume, in this cases the network manager don't show the available wifi network (same scenario with iwlist wlan0 scan command) for a lot of minutes (5-10 minutes... ). After the network card hung up my home wifi network and no other problem emerge since next reboot.
Some idea to solve this situation?