I was traveling to Brazil for these 2 weeks and I was not planning on use any data there because I would be paying roaming charge.
However, I found out that the phone makes a connection to AT&T's MediaNet and transfers about 53KB of data every night at 4:40am exactly. I have disabled the data connection from everywhere but I cannot stop the phone from doing this.
Also, I checked back my data log on the phone, it turns out the phone does this every single day ever since I got it except I didn't notice it when I was under unlimited data coverage. It also does this at 12:40am in Pacific Time and at 9:40am eastern time, so it is not related the clock my phone is on.
The only way for me to disable this is to Change my access point to use a wrong address, so the connection will fail.
I actually setup an alarm and woke at 4:39am to check who is making this connection but I saw the connection was made and I still cannot tell who is making it.
This is really an annoying thing because at some area I have about 20MB data limit and I don't want to change my access point config every night to prevent my phone from using data for nothing.
Does anyone also having similar problem and maybe check your phone log to see if this is happening to you too?
Please post here if anyone has any idea on which program is using it and how to disabled it.