problem with the hostapd demon

[Roberto Guida]

Hi folks!
if i try to start the hostapd demon i get:

[root at PCGUEST9G9 ~]# service hostapd restart
Arresto Hostapd:                                             [FALLITO ]
Avvio Hostapd: Configuration file: /etc/hostapd/hostapd.conf
ioctl[PRISM2_IOCTL_PRISM2_PARAM]: No such device
Could not enable hostapd mode for interface wlan0
hostap driver initialization failed.
rmdir[ctrl_interface]: No such file or directory
                                                              [FALLITO ]


what does it mean?

thanx a lot!
Rob