Default An app - tomtom

I wanted get rid of it's data transfer.
Despite fact that I switched off it's internal transfer setup and my droidwall lock is preventing communication of this type - it still gets data flow as crazy, 30Mb transferred during 3 hours according to BBS.
Q is - HOW ?
What layer allows it when data transfer is off ?
Telephathy ?
I even switched off data transfer completely. No impact ... Still data transfer digits go up...