PS3 compatible with D_link DSL-320B Router?

[#1]

I've been with Plusnet for a few years and have the D-Link dsl-320b router and recently bought a PS3 but whatever I do I cannot get online with the PS3.
Never had any problems with my PC but the PS3 keeps throwing up the DNS error. I've tried multiple DNS codes including the ones given on here but nothing seems to work.
Looked at the D-Link website for downloads for upgrade firmware and the 2 they have aren't a recognisable format?
Anyone help me out or do I need a new router?

[#2]

Firstly:
Id set the PS3 to have a static IP.
Then put the PS3's static IP in the routers 'DMZ' (this turns off the firewall for the designated IP)
However you didnt state what DNS 'codes' (you mean IPs) you've used.
i always use: 208.67.222.222 and 208.67.220.220 (these are free OpenDNS servers)
You connecting via ethernet or Wifi ?