We have a new version, 1.3.
After this version any updates through the api to incidents or comments will not send an email or a notification to the users.
The reason for this is to prevent overloading our servers when importing/updating a large amount of incidents/comments by api.
If a user still wants these features to work he simply needs to add the add_callbacks=true parameter to the url.
Notice that all previous versions of the api are not affected by this change.