Sikthskies, are you using wireless MAC filtering by any chance? What wireless encryption (WEP, WPA, WPA2, etc.) are you using, if at all? And as far as the PS3 getting online but not seeing any of the media servers, then my guess would be that it's not on the same network or subnet. Also, I highly recommend that you use the Port Forwarding features on your router instead of using the DMZ option, as using the DMZ "exposes your router to the internet."
My advice is to completely open up your router (broadcast the SSID, DHCP enabled, no security/encryption, etc.) just to see if you can connect to the router and the internet. If you can, then start from there and work your way up to see what the issue is. I usually tell people to assign everything on your network a static ip address as the DHCP server on a lot of home routers can be flaky at best, so using static IPs gives you one less thing to worry about to. If for some reason you can't connect to the router, or you can connect to the router but not to the internet, then your next step would be to power off router and your modem for at least 10 seconds. That way the router drops all of the old tables and starts from scratch. Routers sometimes get hosed up and refuse new connections, and modems sometimes get hosed up and deny any access to the internet.
Affter successfully connecting to both the router and the internet, here's a quick and easy way to set everything up while keeping it fairly secure. I'm typing all of this from memory, so if there's something that I mis-typed, got wrong, or forgot to add, I apologize. The following is how I do everything on my Linksys WRT54GS, so some of the terminology that D-Link uses might be different:
- Go to the Administration section of your router to get to the Configuration Management section. Backup your current configuration. In case anything below messes up and doesn't work, you'll have a working configuration file handy that you can restore.
- Change your router's default login password, and change the username if the router supports it.
- Disable DHCP on your router
- Change the router's default ip address of 192.168.0.1 to something like 192.168.10.1, and a subnet of 255.255.255.0.
- Disable DHCP on Media Server #1 and change the ip address to 192.168.10.10 with a subnet mask of 255.255.255.0.
- Disable DHCP on Media Server #2 and change the ip address to 192.168.10.20 with a subnet mask of 255.255.255.0.
- Disable DHCP on the PS3 and change the ip address to 192.168.10.30 with a subnet mask of 255.255.255.0.
- Disable the broadcasting of your wireless network's SSID (network name).
- Enable the highest level of wireless encryption supported by all wireless devices. WPA2 is probably the most secure option available, but I've heard of the PS3 having issues with WPA2. Therefore, WPA is your next best option. As always, choose either AES or TKIP+AES as TKIP alone is not as secure.
- Enable MAC filtering and set it to "Allow Only" mode. Add the MAC address of all the wireless devices to the allowed list. This means that only those devices with MAC addresses listed will be able to get onto the wireless network.
- Go to your "Access Restrictions" section, and then to "Internet Access". From here you can setup policies allowing which computers/devices you want to be able to get outside of your router (i.e. the internet). You can also designate what time computers are allowed on, From there, add the MAC addresses of all devices on the network, along with their ip address. If you want, you should have the option to enter a range of ip addresses (example 192.168.10.10 - 192.168.10.100).
- Enjoy your network.
Heavy is good, heavy is reliable. If it doesn't work, you can always hit them with it.