Just curious, why did you want a US-model phone to use on a non-US carrier? Couldn't you have got a DHD that was unlocked from the get go, probably with more compatible bands and no AT&T software bloat and BS like limiting the wifi hotspot?
I thought AT&T phones shared 3G bands with only like 1 other carrier in Canada.
Or are you from the US/AT&T and just visiting there?