Users are finding out the hard way why T-Mobile says you need to have a data play in order to have the T-Mobile G1. One user traveled abroad and ended up racking up a $102.85 bill while data roaming. The big twist here is the fact that he had turned off roaming data sync and 3G completely.
Apparently after getting back from a trip to the UK, he gave T-Mobile a call and spoke with several customer service representatives until a supervisor explained the situation. The G1 always accesses the Internet, even when the Internet services are turned off; the G1 will reach out for sending text messages or even placing calls. In the end the customer service supervisor said, "the phone should have been left in the USA to avoid these charges."
It comes as no surprise that at no time this was mentioned during the phone call placed to enable international calling on his plan. The representatives only stated that he would be charged $10 for every MB of data used and that if he simply stayed off the Internet than he would have no problem. He was being charged about $.15 every 3-7 minutes on average whether on a call or not. It looks like our G1 is not going overseas with us.