Although this was good, I was really looking forward to using the maps on the new iPhone 3G with true GPS. I brought a new 3G iPhone home last week, gleefully clicked on the Maps and “locate me” buttons, and instantly found myself on a map centered on Wayzata, Minnesota. I’m sure it’s a fine place, but unfortunately, I’m 1300 miles away in Utah.

It seems the “assisted GPS” in the iPhone 3G is getting the wrong kind of assistance. It uses cell towers to locate itself before using GPS, in order to speed up the normally slow GPS satellite lock process. This works for most people, but some of the 3G towers are incorrectly listed. The one near my house, apparently, is listed as just outside of Minneapolis. This “assistance” overrides the GPS chip so I’m completely unable to get an accurate GPS location anywhere near my home.

At first this seemed like an odd defect in my phone, but several other Utah locals, including my wife, have the same problem. In addition to Utah, it looks like there is at least one other glitch in the database: several people in Oregon have iPhones that believe themselves to be in Texas.

As reported elsewhere, turning off 3G solves the problem. If you turn off 3G, then locate yourself on the map, it will correctly lock on. Unfortunately, as soon as I turned 3G back on and opened the map, it did a lightning-fast scroll across the country and brought me back to Wayzata, MN.

Several of our friends say that resetting or restoring their phones solved the problem, but that hasn’t worked for us. I think it occasionally works because the phone reaches a different tower, or a non-3G signal, after resetting.

I’m sure this can easily be fixed with a software update, but in the meantime, I’m not exactly thrilled by the iPhone’s GPS performance. Considering the lack of press, I think it’s a very isolated issue. Is anyone outside of Utah or Oregon having similar troubles?

Update 2008/10/07: As of a few days ago, the problem is fixed. 3G gets me an estimated location quickly everywhere I’ve tried it, and GPS locks in shortly thereafter. This did not coincide with an iPhone update, so I think AT&T fixed something in their network.