VAPs and addresses

[aloysius at lavabit.com]

   Hello,
I've just switched from madwifi to ath5k and I'm having troubles adapting
my previous configuration.
I've set two APs with distinct WPA-PSK bound to wlan0 and wlan1
respectively: I set up wlan0 in /etc/network/interfaces and hostapd brings
up wlan1, but then I have no way of setting its IP address.
I've also tried creating wlan1 via 'iw' and configuring it beforehand, but
once hostapd is launched, the address is reset.

Any hint will be greatly appreciated!
(debian squeeze, hostapd 0.7.3)