There is still an issue with the Intel Centrino Wireless-N 1000 adapter and resuming from suspend in Ubuntu 13.04. After resuming from a suspended state (eg. re-opening the laptop lid after it had been closed) the wifi adapter is unable to connect to an access point. The following iwlwifi error would show up in dmesg: “fail to flush all tx fifo queues”
I am using kernel version 3.8.0-23.
To solve the problem, edit the file /etc/modprobe.d/iwlwifi.conf and add the following option setting for the iwlwifi module:
options iwlwifi bt_coex_active=N
The following bug report led me to this solution: Wireless does not connect after suspend/resume