Hey,
I made a regristration to explain you the reason I found out.
The Android OS App does not cause any kind of data usage. It is a provider reason.
Follow this example:
Youre surfing a litte bit in the internet and you use 15kb of data.
But your provider accounts you 100kb of data because of the tact. In many cases low priced providers do this.
So now the Android OS displays the difference of your own data usage and the data usage the provider invoices you.
The same procedure is with the phone minutes. E.G. youre calling someone for 10 seconds, you have to pay for 1 minute...
I noticed it because i'm from Germany and got Vodafone as a prrovider and never had any problems with it.
Now im in the US and bought a Tmobile Sim card, where i got the problem of high data usage in Android OS.
You cant stop this problem except you stop your mobile data or maybe changing to a better provider.
You can only make the problem smaller if you reduce your internet usage, but the Android OS wont stop taking data in every active session. The smaller your data usage the smaller is your android os background usage.
I found a German page that explains the problem in detail:
http://www.teltarif.de/mobilfunk/internet/taktung.html
But til now I havent found any information from tmobile that shows in which tact they account the data. Maybe some of you got something?
I hope you understood what i wanted to say.