Problem AP utility doesnt see AP

I have D-link 700 AP for wireless connection from my lan (i got fixed
IP)
I can correctly connect to desktop pc and laptops in my house but... I
cannot configure AP Mangaer utility in order to set a security
password! Actually I can see other users (probably in my same
building) entering my net! :-(
problems are:
- I can't configure via web the AP...typing my i.p. on the browser
doesnt work...
- I cant configure the D-Link700 AP from the software because
(although my connection to the net is working properly) the software
DOESNT recognize any AP...

Anyone got some idea to help me walk out of this hassle??
thanks from Italy..