"ASUS" A716 The page you are looking for cannot be found"

When I bought my ASUS A714 I had a good WiFi connection to my SMC7204BRB
ADSL modem I could download emails and browse.
But now the connection is still very good,  but I am not able to access the
internet anymore.
IE gives "The page you are looking for cannot be found" whatever I do
(disable encryption, no WEP key, ect)

I have seen this problem been posted in other newgroups before, but never
saw the solution.
Who can help me ?