I have a user that i thought was crazy until i went and tested this. While she is talking on her 3904 and she receives a text on her cell phone the notification alert on her iphone (the notification was set to the default of "Note") depending on what the other user was on (another 3904 our new 3cx system or a cell phone) on cell phone it would sound like it was transferring you to a fax with that slow tone but on other devices it would cause the user to loose audio of the person on the other end she couldnt hear me but i could hear her and sometimes it would totally just disconnect the call. we narrowed it down to the Note tone once we changed that to a different notification tone the issue stopped but is there any other way to fix this?