I've only recently upgraded to Ubuntu 15.04 from 14.04 and I noticed, unlike 14.04, my wireless power manager was turned on by default. It turns off ok with the
sudo wlan0 power off
But is back on after reboot. I've hunted for a solution and have tried the solutions on this page here: Power management for wireless unable to turn off in Xubunu 15.04 Vivid but none of it works. Here's a print out of my iwconfig output, any help would be appreciated...
wlan0 IEEE 802.11abg ESSID:"Pretty Fly For A Wifi" Mode:Managed Frequency:2.437 GHz Access Point: E0:75:7D:D5:06:A0 Retry short limit:7 RTS thr:off Fragment thr:off Power Management:on