Out the gate you should put your ps3 to a static IP, in the DMZ for your router. Google that shit bitch what do I look like?
get yourself a decent router, and update the firmware on that motherfucker. Doesn't nessicarily have to be an expensive one. Some older routers work good, just check the speeds it can handle.
Linksys WRT54G worked for me until lightening struck, now i'm running an e 3000 with a built in media server. the built in media was garbage, idk if they fixed the bugs i haven't checked for updates for a minute....
use this if you have problems with windows media player server I recommend: