Listen to big9erfan
What you want to do is manually enter an IP address. find one from your router, itll usually be 192.168.#.#
so how you do this is: find your default IP. easiest is to look on the network info screen by pressing that (>) button thing. then you will see ip subnet mask router and dns.. copy down the subnet mask, Router, and DNS numbers..
click on static, that stuff will all disappear. type in your subnet mask, router, and dns. Your ip address will be a number not the dns.. eg DNS: 192.168.0.1 IP: 192.168.0.13 and 192.168.0.19
this should prevent you from clashing.. though why it did it in the first place is beyond me. if you ever want your normal settings back, click on DHCP, scroll down and press Renew Lease. the list will repopulate.