Ad-hoc wireless... Help?

[Gilboa Davara]

Hello all,

I'm trying to setup a temporary ad-hoc wireless connection between my
firewall (CentOS5) and my laptop. (F9, NM disabled)
The wireless connection will sit on the "red" side of the firewall (and
will be disabled most of the time), so passphrase security should be OK.
(At least for now)

As far as I could gather (By using google), I should issue
(more-or-less) the same commands on both ends.
E.g.:

FW: (rt61)
$ ifconfig ra0 192.168.200.1 up
$ iwconfig ra0 channel 11 rate 11M key XXXXXXXXXX essid name

Notebook: (Intel chipset)
$ ifconfig wlan0 192.168.200.2 up
$ iwconfig wlan0 channel 11 rate 11M key XXXXXXXXXX essid name

Ping doesn't work; ARP doesn't resolve IPs.
What am I doing wrong?

- Gilboa

P.S. AFAIK the rt61 driver doesn't support Master mode, so I cannot
setup an AP and I rather not use a permanent wireless AP.