Laptop unable to obtain correct IP address

Hello,
Hope you can help. My friend and i both have the same ADSL Netcomm modem N5+4W, on which the wireless network is setup identically with the same SSID and password. When she is at my place the laptop connects automatically to my nework, however when she goes home it is unable to connect and the IP address of the laptop changes to 169.254 etc. If i change the ip address in the TCP/IP properties to 192.168.1.6 the wireless connects to the network but the internet is unable to display a webpage. As soon as I change it back to obtain an address automatically it reverts to the 169 address.
A point in the right direction would be very much appreciated