Confusing

Last night, just as the 11:00 p.m. news started, I glanced down at my iPad and saw that it was happily communicating the fact that it was 10:48 p.m. It was a good twelve minutes off from the actual time! How the heck can that happen? The thing constantly connects- via wifi or 3G- to all kinds of web sites and apps that keep track of the right time, and it's been constantly demonstrated to me that my iPad always knows exactly what city, state, and timezone it's currently residing in. So what gives?

The Date & Time area in Settings is set to Set Automatically (I checked), so I don't know how this happened, or when. The time must have jumped the track recently, I'm guessing, or I would have noticed it earlier. Anyway, I fixed the time, but now I'm watching things closely to see if it drifts again.

Has anyone else had this problem?