I'm pretty sure it's not the APN, used the same settings on another phone, just switched sims.
My location is Trinidad, and my carrier is bMobile (Cable&Wireless)
And 4G still works when I put the sim back in the other phone ( A Samsung Galaxy Note)
edit: I tried wiping, rebooting, switching the data on and off.....even flashed over the stock ROM, still no go. Just edge.
History on 'droid...
Previously: Motorola Milestone, Motorola Xoom, HTC Desire
Currently: HTC Desire HD, Samsung Galaxy Note, Samsung Galaxy Note 10.1