People using Raspbmc (including me) tend to have problems with installation of TP-LINK WN725N v2 (v1 works out of the box). I have no idea why tp-link didn’t change model name when they changed the chipset but that’s reality that causes a lot of confusion. Anyway, installation is very simple and consist of 3 steps.
sudo wget http://raspberry-at-home.com/files/8188eu.ko -O /lib/modules/`uname -r`/kernel/drivers/net/wireless/8188eu.ko
sudo depmod -a
sudo modprobe 8188eu
That’s it! Check network-manager plugin – it should work now…