We try to send the ringtone in the best format for each phone, but sometimes we don’t get it quite right. You can always try some of the other ringtone formats we have available.
Just go to the Account -> Phone Preferences page and select a different format from the Ringtone Format list, then follow the link in the original message to download the ringtone with the new format. If you have already deleted the original message, you can just go to your homepage and resend your ringtone from the Recent Downloads list.
If you find a ringtone format that works better for your phone, please let us know so we can update our software.