problem with wifi

<turtlehat> hellose gaise
<turtlehat> i have set up wifi on my pi, and i can ping it fine, but i cant connect to ssh
<turtlehat> what gives
<turtlehat> raspbian
<turtlehat> and i can see that right after i try connecting to ssh on the wlan0 interface, it stops responding to pings
<turtlehat> but if i then plug my ethernet cable, connect to the ethernet address, ifdown wlan0 && ifup wlan0, then i am able to connect to ssh on the wlan0 interface
<turtlehat> what the fudge gives



root@twopi:~# cat /etc/network/interfaces
auto lo
iface lo inet loopback

auto eth0
allow-hotplug eth0
iface eth0 inet dhcp


auto wlan0
allow-hotplug wlan0
iface wlan0 inet dhcp
wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf

iface default inet dhcp





root@twopi:~# cat /etc/wpa_supplicant/wpa_supplicant.conf
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
#update_config=1


network={
	ssid="xxxx"
	psk="xxxxxxxxx"
	id_str="xxx"
}