Default route doesn't change to wireless device (ath0)

Hi!

If I plug in my wireless nic (atheros) it comes up automatically through 
wpa_supplicant. However the default route still points to my non wireless nic 
(fxp0) even if remove the network cable before plugging in the wireless 
device. I have found no way around this, the only way of getting the default 
route changed to ath0 is setting in manually. Can't that be done 
automatically on plugging in either? 

Jochen