I downgrade to kernel 2.6.37 from http://kernel.ubuntu.com/~kernel-ppa/mainline/v2.6.37.6-natty/. Wifi connection works right after boot of system. I think this is regression in aht5k from 2.6.37 to 2.6.38 linux kernel.
** Attachment added: "syslog_2.6.37" https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/781771/+attachment/2127462/+files/syslog_2.6.37 ** Also affects: linux Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/781771 Title: ath5k long wifi search and connection after system boot -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs