Hopefully, the firmware update will help. I was having similar issues a month or so ago with one of my laptops intermittently dropping connections. Then one day I couldn't get to the net with any of my PCs. Could connect to the router and the router could see the net, but none of the computers could get through.
After updating the firmware, all has been solid since. I didn't have a PS3 in the mix at the time, but I doubt the PS3 is causing the issue with the router.