Here's a tip for all you security and enterprise types - iOS 4 offers iPhone owners a way to protect their data ... but upgraders need to do some legwork to get it working.
iOS 4 offers data protection for iPhone 3GS and 3rd-gen iPod touch owners. This enhances the built-in hardware encryption by protecting the hardware encryption keys with the access passcode thus provides an additional layer of protection for email messages and attachments.
But the problem is that if you upgraded to iOS 4, this protection isn't on offer unless you restore your device and then reload all the data from a backup.
Use the following steps to back up your data, restore the device, and then restore your data from the backup:
1. Connect your device to iTunes and back up your data. 2. Locate and right-click the device in the left-hand column of iTunes, and then select backup. 3. When the backup is complete, locate and click Restore in the Summary pane. 4. When the restore is complete, select the option to "Restore from a backup" in iTunes and pick the backup you created earlier. - Note: iTunes automatically selects the most recent backup; you can verify this by checking the date and time the backup was made. 5. Follow the directions to restore the backup. When the restore process is complete, set a passcode to enable data protection.
iTunes will download and reinstall iOS 4 on your device.
It's a bit of hassle, but it's worth it.