Back when there was a lot of fanfare, I bought an "unlocked" Dell Streak right from the dell.com web site. It arrived, and it was pretty clear they'd rushed it out the door with a kluged together Android 1.6 installed on it. It was an unmitigated heap of garbage. But they promised a forthcoming update to Android 2.2, with unlocked units getting the update as soon as it was available.
It turns out that most of the "unlocked" units (purchased at additional expense, since you didn't sign a contract with a carrier) were actually locked to AT&T. You can't get the update. Dell lists a manual download in their FAQ, but that one fails to install. Doing a manual check for new system software results in a message that you're up to date. Nothing works.
Well, from the seventy-fifth page of a thread on Dell's self-support forums, here's the update, which will install on your "unlocked" Dell Streak that's actually locked to AT&T. Download it on the Streak's browser, then tap it to install:
It installed for me! If you're in the same boat, I hope this helps. Hopefully this cleans up some of my issues. If not, I can just throw it back in the closet for another six months..