The default ringing tone is played instead of the user-defined ringing tone if the system resources are low and there's not enough resources to play the user-defined tone. The device will revert to the default tone if it takes too long time to start playing the user defined tone. The issue may occur e.g. when there's a large number of applications concurrently active or if there's some other constraints preventing the music tone to be played within the allocated time. 

The issue is usually temporary and the following actions will help to ensure that the device can properly play the user defined tones:

  • Close some of the applications if there are many applications active at the same time. Press and hold the menu key to see the list of currently active applications.
  • Use small files for ringing tone, avoid using large music files.
  • If an image is attached to the contact details, avoid using large images (displaying of a large image or photo at the same time when starting to play the ringing tone may cause resource issues).
  • Move the ringing tone file to C: Phone memory to speed up the playing (remember, though, to keep your other music files on the mass memory to avoid filling up the phone memory).

Improvements for handling of the ringing tone are included in N97 version 22.x.110 and N97 mini version 12.x.110. It is recommended to upgrade to these (or later) software versions if available for your device.

Note that if the ringing tone file is located on memory card, the tone will change to Nokia default tone if the memory card is removed.