USPS does that. 9400111899560207356129 is a tracking number for something I just ordered that shows the same thing.
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Maybe the snowy weather condition?
http://i57.tinypic.com/vid1e9.jpg
It's a given. USPS tracking is a joke.
They are good for one thing only, and something that's rarely needed - USPS Postal Money Order. Good as Gold.