Hey, were you able to come up with ANY info on this problem?
i have had this problem since i got my iphone5 in february/2013, and its continued onto my new iPhone5S.
The best i could come up with, through research and first-hand experience is that the "Facebook" and "twitter" tone options DO work, but only when it is an OUTGOING action YOU PERFORMED (ie a tweet that YOU posted, or a facebook post that YOU posted)
and since newer iphones have facebook and twitter integration, The facebook and Twitter tones also work for facebook Chat/messages that you receive, and twitter direct/instant messages that you receive.
As for the other types of notifications that you get from facebook and twitter (ie. Wall posts,being tagged in photos, twitter mentions/@replies, or notifications from people you are following{if turned on})
:::these notifications seem to fall into the same category of MOST notifications from ANY App that you download from the app store.
It seems thats MOST apps do not have a specific notification sound programmed, and ANY notifications that you have selected to receive are carried out with a "default" Apple Notification tone (which appears to be the classic Tri-Tone).
I have arrived at this conclusion because in the Settings->Sounds menu, only Device Functions are listed and thus able to have their Tone Changed.
ALSO; in Settings->Notification Center, You will notice that when you click on the various 'apps' listed:
*****'Stock' Apps (Messages, Phone, Facetime, Reminders, Calender etc.) have sub-options to change the name of the 'Sound' 's Tone (which appears there)
*****while ALL OTHER Downloaded apps only have a sub-option slider/knob to turn the 'Sound' either 'ON' or 'OFF'
Since there is no option to select a 'Tone' then it is safe to assume that the activated 'Sound' is the Device's default tone.
THEREFORE...if there is no options -WITHIN THE APPLICATION ITSELF- to change the Sound or Tone of their Notifications...the question/objective Now seems to be: How can we change our Device's default Notification Sound?
<Edited by Host>