Immediately after updating to iOS 4.0, some users may notice that Exchange ActiveSync Mail, Contacts, or Calendars do not sync, or sync very slowly. In addition, some Exchange Server administrators may notice their servers running slowly.
When I play music or listen to a call through the speaker phone, the sound may appear low or muffled, or the person I’m talking to claims that I sound muffled or not loud enough.
Learn why the storage capacity stated in a product’s specification may be lower than what is reported by Mac OS X or iOS.
When syncing a device using iOS 3 or later, syncing may stop with Error 13019.
Learn how to find out which version of software is installed on your iPhone, iPad, and iPod.
It is important to create frequent backups of important data. This is even more important if you are using beta software. You should make sure you back up your data prior to entering the MobileMe Calendar Beta.
iMovie will sometimes quit while exporting if your project contains several still images.
iPhone displays an "Inbox is full" message when attempting to check voicemail. This message indicates that your AT&T voicemail box is full, so you need to delete messages that are stored on the AT&T voicemail server.
This article explains how to ensure that you are deleting voicemail messages that are currently stored on the AT&T voicemail server.
After upgrading to iOS 3.x or iOS 4 or later you may be unable to use some Cellular Data Network services, such as:
Cellular Data connection for Internet services
Visual Voicemail
MMS (Multimedia Messaging Service)
Internet tethering
You may also see this error message: "Could not activate cellular data network: You are not subscribed to a cellular data service". This can happen if you edited the Cellular Data Network settings—the APN (Access Point Name) details—either manually or with the iPhone Configuration Utility prior to installing iOS 3.
Note: This issue does not affect phone services (making and receiving calls or sending and receiving SMS messages).
You may encounter the following issues:
You are unable to receive MMS messages
You do not see the camera icon next to the message field:
A red exclamation mark appears next to MMS messages you send:
Note: MMS is not available for original iPhone