I updated to 13.10 yesterday and noticed that wireless power management is on permanently, effectively making my internet connection uselessly slow. I previously had edited /etc/rc.local and added iwconfig wlan0 power off to the end of the script so power management would be turned off. Now, even if I run wlan0 power off in the terminal I get the following error:
Error for wireless request "Set Power Management" (8B2C) : SET failed on device wlan0 ; Operation not permitted.
This operation was "permitted" in 13.04 and worked great, I'm regretting updating as I finally had everything working great. Guess I've learned my lesson with updates now! FYI I have a samsung series 5 ultra notebook. Thanks for your help.