can't connect to AP by telling iwconfig the MAC address (orinoco_cs)

Hi,
I'm using Knoppix linux with kernel 2.4.22-xfs and a prism 2 wlan card (
orinoco_cs ).
My wlan card connects automaticly to the AP with the strongest signal,
but I want a connection to anotherone with the same essid.
If I tell iwconfig the mac address of the AP, I get the following error msg:

root@foobar:/home/znoopy# iwconfig eth1 ap 00:01:E3:03:30:6E
Interface eth1 doesn't support MAC addresses
eth1 Interface doesn't support MAC addresses
Error for wireless request "Set AP Address" (8B14) :
invalid argument "00:01:E3:03:30:6E".

What's wrong ?
is it a driver- or a hardware problem ?

iwconfig give me these information:

eth1 IEEE 802.11-DS ESSID:"znoopy" Nickname:"Prism I"
Mode:Managed Frequency:2.447GHz Access Point:
44:44:44:44:44:44
Bit Rate:11Mb/s Tx-Power=15 dBm Sensitivity:1/242700000
Retry min limit:8 RTS thrff Fragment thrff
Encryption keyff
Power Managementff
Link Quality:0/1 Signal level:-68 dBm Noise level:-122 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:0 Missed beacon:0