WiFi tx-power setting

[andrew01]

Hello,

I'm using Kubuntu 7.04 on IBM T41 with
latest drivers and firmware and
I trying to change a tx-power on
Intel Pro Wireless 2100 card with that command:

sudo iwconfig eth1 txpower x

I tried x=0, 1, ... , 10, 10dBm, ...
but it doesn't work. I always have Tx-Power:16 dBm

What I am doing wrong?
I also have strange output for command:

iwlist eth1 txpower

which is:

eth1 unknown transmit-power information.

Current Tx-Power:16 dBm (39 mW)

Thank you for any help.

Andrew