Solution is simple. Go to Menu -> Tools -> Settings -> Connection -> APN control. A message will say "Reading content from SIM card". After that, it should display another message "Connections restrictions inactive". If it does not, go to Options -> Deactivate restrictions. Exit all the way back to the standby display and try web browsing or sending a MMS.
The help page for "Restrict connections" is described:
With the access point control service, packet data connections from your device may be restricted to certain access points only.Let me know if this works for you.
Your SIM card may not support the access point control service. Contact your service provider for more information.
The following is a good site to be updated on Nokia software updates, which recently announced firmware version 12.046 for the Nokia N78. This release includes performance improvements for softkey selection, Bluetooth stability, video playback, e-mail sending and alarm clock functions.
<URL:http://europe.nokia.com/A4577225>
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