I patched the zd1211b Atheros chipset USB, like this :

Copy zd1211rw_inject_2.6.20.patch to /usr/src/linux/

cd /usr/src/linux/

NOTE: In the following lines, verbose and dry-run have a double dash in front of them.

patch -Np1 --verbose --dry-run -i zd1211rw_inject_2.6.20.patch

If it was OK:

patch -Np1 --verbose -i zd1211rw_inject_2.6.20.patch

Copy ieee80211_inject.patch to /usr/scr/linux

patch -Np1 --verbose --dry-run -i ieee80211_inject.patch

If it was OK:

patch -Np1 --verbose -i ieee80211_inject.patch

NOTE: In the following lines, change “2.6.20-1.2944.fc6” to match your particular system.

cd /usr/src/linux/drivers/net/wireless/zd1211rw
make -C /lib/modules/2.6.20-BT-PwnSauce-NOSMP/build/ M=`pwd` modules
cd /usr/src/linux/net/ieee80211
make -C /lib/modules/2.6.20-BT-PwnSauce-NOSMP/build/ M=`pwd` modules

Now copy the new modules to the /lib/modules tree to be used.

cp /usr/src/linux/drivers/net/wireless/zd1211rw/zd1211rw.ko /lib/modules/2.6.20-BT-PwnSauce-NOSMP/kernel/drivers/net/wireless/zd1211rw/zd1211rw.ko
cp /usr/src/linux/net/ieee80211/*.ko /lib/modules/2.6.20-BT-PwnSauce-NOSMP/kernel/net/ieee80211/
cp /usr/src/linux/net/ieee80211/softmac/*.ko /lib/modules/2.6.20-BT-PwnSauce-NOSMP/kernel/net/ieee80211/softmac/

At this point, the simplest method to bring up the new modules live is to reboot your system.
This is from aircrack-ng.org/doku.php?id=zd1211rw
But now when I start aireplay-ng than airodump stop and say wrong radiotap header version. I did just what I described and nothing else.
Can someone pleas tell me what I did wrong ?