wpa_supplicant is unable to associate with my phone (which acts as an ad-hoc peer).
I have set up the wpa_supplicant.conf on F16 as follows:

network={
    ssid="MyPhoneSSID"
    bssid=xx:xx:xx:xx:xx:xx
    scan_ssid=1
    mode=AD-HOC
    key_mgmt=NONE
    group=WEP104 WEP40
    wep_key0="wep_key_0"
    wep_key1="wep_key_0"
    wep_key2="wep_key_0"
    wep_key3="wep_key_0"
    wep_tx_keyidx=0
}

Association never takes place.

However, my Apple/OS_X  laptop has no problem associating with same phone.

So, what is wrong with my wpa_supplicant.conf file?