I suspect something else is accessing the net, running in the back ground.

Not got a clue about android, but is there a task manager app of some sort, so you can see everything thats running.

send him in this direct, for a lot of searching and brousing,

http://forum.xda-developers.com/forumdisplay.php?f=594


Also a full reset and upgrade to the latest version of his OS will probably do wonders