In theory your router will now assign an IP address to whichever PC or Ps3 is connected (router treats both as a PC or internet device) so you shouldn't have the problem again.
Without knowing the router you are using I can't help further.
Your router manual should give you instructions on how to assign a dedicated IP address to a specific device(if it proves neccessary) ie your PC will have it's own and so will your PS3. Routers as a norm have 99 IP addresses to assign so the problem should not surface again.
As an example I have 3 PC's connected via a Belkin router the Router IP address is 192.168.2.1 That is the address of every Belkin Router but not my IP provider, so no security risk in putting it here.
My main PC uses 192.168.2.2 and the last figure changes with each PC. If you do nave future problems just unplug the power from your router and reboot it and it should sort it out itself.
Edited by Pippincp, 21 January 2008 - 07:11 PM.