Ps3 internet issues

Hello,
I'm having issues with my ps3 getting internet connection when my main pc downstairs is on. It connects fine when it's off. It worked fine before when both machines are on but now i doesn't. It is a wireless connection and i have set up its own ip address. I have also disabled media connection and still no joy. I have had this problem before when my ps3 need an update but have checked and there are no new updates. Any help would be great.