I've gone through every troubleshooting step Blizzard has to offer, been on the phone with my ISP and Blizzard for countless hours to no avail.

When oQueue is disabled, no lagging out or disconnects.

What can I do to stop/fix this? It has been going on for a very long time (5-6 months)

We have been unable to reproduce this issue.

Might you try running arena with only oQueue enabled. If you do not lag out then there may be a conflict with oQueue and another addon which is causing issues.

If you still lag out, when you enter the arena you can try doing /oq off to disable oqueue while you are in the arena.

We are still looking for why this is happening, but was it does not happen to use, it is hard to troubleshoot.

Have people been having problems with ElvUI and oQueue?

Yes, ElvUI is a addon which is involved in a number of conlifcts with oQueue. These conflicts usually pertain to group invitations though.

I've never had problems with group invites, just disconnects in arenas.

i've been running many arenas recently and have not disconnected once during any of them.

i also run with few addons and my box is generally pretty good (quad core w/ hd 6950)

my network is also generally ok, as my bandwidth is 20Mbps dn and 2Mbps up (a piss poor bandwidth imho, but it's about all they've got)