Talke to ATT twice, to confirm what the 1st agent told me.
SUBJECT:
iPhone International Roaming
FACT:
Apple iPhone
iPhone users roaming internationally need to be aware of the following:
The unlimited data portion of the iPhone rate plan is limited to domestic use
Data is not unlimited when roaming internationally. When using your service outside the U.S., Puerto Rico or U.S. Virgin Islands, international roaming rates apply.
Decreasing International Data Usage
In order to decrease international data usage, the following options are available to limit automatic or regulated data sessions.
Disable Email Retrieval
Tap Settings.
Scroll down and tap the Mail icon.
Tap the first integrated email account.
Slide the email indicator from On to Off .
Click the Mail icon in the upper left hand corner.
Repeat for every integrated email account.
Each account must be turned back on to resume delivery and receipt of email messages.
Airplane Mode
Tap Settings.
Slide the Airplane Mode indicator from Off to On.
All voice and data functions of the device are disengaged until this setting is set to Off.
These tips can also help you minimize data usage while roaming internationally:
Utilize WiFi, available in many international hotels, airports, and restaurants to browse the web or check email
Keep Data Roaming "OFF": Be sure to download the Version 1.1.1 upgrade to iPhone. This software update will enable the ability to turn on/off data roaming when traveling outside the U.S . By default, this setting will be in the "OFF" position. The path is: Settings > General > Network > Data Roaming.
Turn off your phone's "auto check" function, and check email manually when needed, using WiFi
Reset the usage tracker to zero when you arrive overseas and monitor your data usage
Consider purchasing an international service plan that includes discounted international data usage. AT&T now offers two discount international data packages. The 20 MB package is $24.99; the 50 MB package is $59.99. See att.com/wirelessinternational for details and international roaming rates.