If you run 'netstat' from a DOS window while you're connected via TWS, you'll see the addresses you're linked to.
My system is going to 'gw1.ibllc.com' and 'mktgw1.ibllc.com'. Running tracert, I can see both of these addresses are in Boston. Sounds like locating in the NE might be a good idea.
Just on a whim, I also ran tracert tests on gw2, gw3, gw4, gw5.ibllc.com... and they're ALL in Boston.
IB's website claims they have servers throughout the world, but I don't see it. Can other IB customers also run the test, and see if you're being directed towards a different server?