What kind of net connection do you have?

What are your computer's specs? There may be lag from processor speed, ram, graphics card, etc.

The servers are all located in the same place, last I heard - switching wont change your performance.

What sort of lag is it? Is it choppy gameplay, or is it latency-related lag (ie: the bar at the bottom right is in the red, and you see players rubber-banding often)?

In the first event, it's a graphics issue (And with your 9250, this is probably your issue). MxO can be a very demanding game if you put it on max settings. Try disabling some options in the Video panel, and see what happens. It took me quite a while until I settled on the most playable settings, and I'm on an x800 GTO - head over heals above your 9250 (no offense intended )

In the second event, it's a network connection. Are you downloading anything while playing, especially a torrent? This will severely effect your network performance, and will often cause disconnections. Though, since I believe you have graphics lag, I won't flesh this one out further.

Let me know if you need any more help or clarification.

Actually it is very possibly to have lag on 1 server and not the other. The best way to confirm this is to ping each server seperately to confirm the connection route is the same for all.

I once had major lag on recursion, but not on syntax, and it turned out to be a connection issue to recursions servers, which was only resolved after a few router restarts.

The main graphic settings that can cause most lag are "Overbright" and "Anti alias" filters.

Also, just to compare, which other MMO's have you tried and not had this kind of lag?

It's a DSL connection, I'm unsure on the numerical speed.

My computer is pretty old, so it probably is that.

2.8 gHz proccessor

1gb with 256 mb of RAM

Radeon 9250 video card.

I know the card is old, but I don't think there is any helping it as this old thing got stuck with only PCI slots. I am intending to replace it this summer actually. 

I'll tell you now, having more recently changed my PC, my old one had a similar spec... the main thing that'll be slowing you down is your RAM.

The all knowing QA man 9mmfu has often spoken about how MxO is a RAM gussling game, so I'd say that was the main thing holding you back.