wlan problem

hi every one!

I have IEEE 802.11.b wireless network with eap_peap authentication on
my college and i am using asus wl-107g wireless LAN adapter (rt 2500
chip set).
Under windows xp every thing works fine but in Linux (FEDORA CORE 4) I
have a problem.
I am using xsupplicant 1.2.2 for authentication. I tried connecting with
wext hostap and ndiswrapper (windows imported rt 2500) driver but no
matter witch driver i use the problem is same.
I can connect and every thing works just fine as long as AP doesn't
change encryption key slot and wen it does the connection breaks.
If the new encryption key is pushed in the same slot everything is ok.

My xsupplicant.conf is as follows
default_netname = FERwlan
logfile = /var/log/xsupplicant.log
FERwlan
{
allow_types = all
type=wireless
wireless_control=yes
identity=<BEGIN_ID><END_ID>
eap-peap {
root_cert=NONE
chunk_size=1398
random_file=/dev/urandom
cnexact=yes
eap-mschapv2 {
username=<BEGIN_UNAME><END_UNAME>
password=<BEGIN_PASS><END_PASS>
}
}

}
of course user name and password are fill in .
I am connecting with this few commands:
iwconfig wlan0 essid FERwlan
iwconfig wlan0 key open 0000-0000-0000-0000-0000-0000-00
ifconfig wlan0 up
/usr/local/sbin/xsupplicant -i wlan0 -z
dhclient wlan0

if someone can use log file i can post it to but it's a bit long so i
thought that this would be enough for now
Any suggestion is welcome!
Thank you very much