No, there's no need to add anything as you're using the right client...

MTU I presume is related to network packet size or something, so unless you have a new/wonky network, I don't think it'd be an issue, though Choko probably knows more about that than myself.

Additionally, you're sure no firewalls are limiting connections outbound and inbound? I really don't know what to say in that case. There's only one case that this has happened in the past, and if you're using a valid OS install, then that shouldn't be a problem either...

While the setting in your router would also need to be checked (since all routers are different, I can't give advice on how to access it)
to be able to see what your mtu settings are, open cmd and run:
netsh interface ipv4 show subinterfaces

Well, despite it always working fine without ever making any changes to my router, I've even bought a new laptop and tried it on several routers and still no go.

Guess I'm not lucky enough to play anymore. v.v

Sorry for the necro but I've decided to retry again and I'm met with the exact same problem again.

I've recently purchased a brand new gaming desktop and wanted to come back here again.

Is there something going on? :s

As Choko said. Its possibly caused by the MTU setting. The fact that it does the same on multiple systems on I assume the same network, it could be the MTU set on the router. Most routers come configured with a MTU setting that is perfectly fine. However I've worked on Cisco routers in the past with a default MTU of 4500 which causes problems.

If your internet connection is DSL the MTU should be lower than 1500. You can generally get the recommended MTU for your ISP from their website/forum.

Also make sure you haven't got any VPN clients running such as hamachi.

I went through my router, there was no MTU option to change but like I also said, I have never made any changes to my router and it worked fine. This problem happened recently and just never went away.

Also, I just tried logging into Schtack and I have no problems there.
But I rather not go to Schtack, I want to be here. Is there anything else I can do to fix this problem?

Well, the last time I couldn't get on Eden for a day was to uninstall some useless program I recently installed. I knew some program was the problem because I was able to get on Ultima just fine.

Have you installed some new programs within the past six months?

Then again, did you fail to connect to Eden on more than one computer?

I haven't made any changes to my software when it worked so nothing new has been installed either.
I've used three computers. A notebook I borrowed for this, my older desktop and my new desktop. Same problem still.

Ok if you can connect to another server it wont be the MTU then.

Can you try running the following from a command prompt window (Windows key+R and enter cmd then click ok):

tracert ragol.edenserv.net

Ideally you'll want to see 15 or lower hops. Any more than that can cause issues connecting to a PSO server. If you are getting higher than 15 it could be a routing issue with your ISP. You should be able to take it up with your ISP if that is the case.

Are you able to test from another internet connection such as a neighbours wifi?