help androids!
my friend has a problem with her t-mobile htc mytouch 3g (smart) phone. she got the phone from US and got unlocked using a key code given from someone in the US pud. she is using pre-paid btw. right now the phone is working (can call, send sms) but her load is consumed even without using. if using Sun sim, the message "7210: You do not have enough load to complete this transaction. Please reload immediately." is received hourly. i think the phone requests something to the network, something like OTA? if using Smart sim pud, wlay msg mareceive but mahurot lang ang load.
is there a solution to this?
i have done enough research already and came across OTA, and an info that android has OTA support but i don't know if this can be disable in any way sa android.
syncronization settings were already disabled. naa pay lain?
if you know the solution, please point me there.

thanks!