Just checked it again and the "Usage Details" only shows logins, all 850 of them, however, the "Data Usage" field is blanked out. Below is an example of one line in list of 850 login transaction.

Date: 12/21/2010
Time: 7:58 AM
Usage Type: MBB 10GB (Mobile Broadband on the 10 Gigabye Per Month Plan)
Data Usage: (blanked out)