As a default since Kubuntu releases 10.10 or perhaps earlier Kubuntu desktop edition is equipped with Network Manager which configures your WIFI networking from desktop and consequently will only connect to network when you login similar to Windows. If you didn't want this and wanted to connect to your workstation without logging in remotely you would have to configure it in a Ubuntu server way.
#Remove Network Manager
sudo apt-get remove --purge network-manager*
#Check if wireless card driver is installed and working
# if it reports no wireless extensions, find out the card and install driver
$ lspci | grep Network
$ iwconfig wlan0
#Modify /etc/network/interfaces and add wlan0 info
auto wlan0
iface wlan0 inet dhcp
wpa-ssid WIRELESSAPSSID
wpa-psk WPAPASSKEY
#Now restart your networking
sudo /etc/inet.d/networking restart
#Remove Network Manager
sudo apt-get remove --purge network-manager*
#Check if wireless card driver is installed and working
# if it reports no wireless extensions, find out the card and install driver
$ lspci | grep Network
$ iwconfig wlan0
#Modify /etc/network/interfaces and add wlan0 info
auto wlan0
iface wlan0 inet dhcp
wpa-ssid WIRELESSAPSSID
wpa-psk WPAPASSKEY
#Now restart your networking
sudo /etc/inet.d/networking restart