I think someone said this is the daily total instead of the actual data from when used. Gets around the problem early Iphone users had where the bills were hundreds of pages long due to all the detail.
Could be something AT&T does... I know VZW does a reset/test/ping early in the morning with Aircards (Barely noticable).. AT&T might do something similiar with thier BlackBerrys.
Have you spoke with customer service yet maybe they could give you a quick explanation? (other then that I'm not too sure.)
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8830 -> 8330 -> 9550 -> 9650
Just think about how far BlackBerries have come from then till now... And what else is coming.
Its the cumulative of the browsing for the past day. It is that early in the morning from my understanding because that is when they reset the data/blackberry servers or something like that. I've called att on this before. Its nothing to worry about