Fujitsu LIFEBOOK T731 Guide D'utilisation page 176

Problem Possible Cause
Unavailable RF interference from
network 
Access Points or
connection other wireless
networks
(continued)
Wireless network
authentication has
failed
Incorrectly
configured network
settings
Incorrect IP address
configuration
Possible Solution
The use of identical or overlapping RF channels can cause interference with the
operation of the WLAN device. Change the channel of your Access Point to a
channel that does not overlap with the interfering device.
Re-check your Network Authentication, Encryption, and Security settings.
Incorrectly configured security settings such as an incorrectly typed WEP key,
a misconfigured LEAP username, or an incorrectly chosen authentication
method will cause the LAN device to associate but not authenticate to the
wireless network.
Recheck the configuration of your network settings.
This only applies to networks using static IP addresses. Please contact your
network administrator for the correct settings.
175 Troubleshooting the WLAN