802.11 WPA and wpa_supplicant

Hello,

I'm playing with WPA-PSK (AES and TKIP) with my Linksys
WRT54G on recently current, but no luck :(

Basically I use [http://people.zoy.org/~hpreg/wifi/] to set
up my ap and wpa_supplicant. Somehow, I can associate
to the ap and ifconfig ath0 does show the key. but i can't
send any packet or receive any packet. I found that the
transmission key is changing every 1 second?? I don't
think this is right.

My notebook is IBM X31 with built-in Atheros a/b/g.
And wrt54g's wpa-psk works fine under windows.
So, is there any information that i can provide to work
this out?

Regards,
Rong-En Fan