802.11b mode on wlan interface

Hello!

I'm using -CURRENT on my Acer Aspire One (Atheros 5424/2424). Thanks to
the lastest ath_hal (0.10.5.10), the device is correctly attached.
However, I can't test it right now, because I have an old 802.11 device
that only works in 802.11b mode.

I tried to set manually the mode using ifconfig, but no go... :(.

I tried setting the mode (11b) on the ath0 interface and wlan0
interface. Also setting the mode in rc.conf doesn't work at all.

Anybody had this problem?

Thanks in advance,
Thiago.