I always get incorrect results for anything that uses the location feature in Firefox 3.5. This time it put me in Chicago, but I've been put in NYC and San Fran

I always get incorrect results for anything that uses the location feature in Firefox 3.5. This time it put me in Chicago, but I've been put in NYC and San Francisco before as well. I'm NEVER in the correct location (Pittsburgh). I'm running Ubuntu for what it's worth. You would think that it would do a reverse DNS on the IP at least to make sure it gets the city correct...