I'll give all the info I feel is relevant

So, after coming back to wow about a week before 4.0.1 was released. New account and new internet, playing with aprox 33ms on the misery battlegroup. I live in Norway and I chose the misery bg for the sole purpose of having as good connection as possible (located in sweden)

Everythign is fine in dungeons, normal world, raids, bg's you name it. Except for arena, there's this huge delay going on for soem reason and I can't for the love of God find out why. For a second I thought it had something to do with my internet, but after getting my very own internet a couple of months ago the same problem persisted and I'm sorry. I just no longer believe that it's my internet causing only delay in arena and never in any other place.
I also recently changed BG and same problem here

It's not like my ms skyrockets, it stays at around 43 now (paris realm) but there's still some delay going on. It feels like the exact thign as when a realm is overpopulated, while ms stays steady there's constant delays to everything
I wasn't bothered at first during cataclysm because I was unhappy with warriors and didn't fee like doing any serious pvp anyway, however with MoP I wanna get at it again and this just HAS to be fixed somehow. It's driving me crazy, especially when warriors with stance changing and weapon swapping is essential and is so heavily dependent on ms

Any help?
I'm not too good with computers so I don't know if I'm capeable of getting all the info you want unless you give a brief explanation how, sorry