Your problem is due to a software malfunction at your local at&t tower (many have not been updated to the new DST schedule). I run into similar problems all over the place. Some towers near me right now are off by as much as 6 hours. You will also have problems if you are near any of the time zone divisions, as one tower will tell your iPhone one time, and another will give it another time. You may also encounter this kind of problem if you drive across the US, especially in the Mountain Time Zone, for some reason, no at&t/cingular phone I've ever had would automatically update the time zone when driving through Montana. However, if shut the phone off and then turned it on it would display the correct time.
Your best bet, for now, is to set the time manually (which will sync the iPhone's time with your computer, which in turn syncs with Apple's time servers) until next week, or longer depending on what your local tower problems may be.
TEG