as a follow-up to my original post, in case someone else besides myself is interested in having the notification bubble but not the "ding" sound when sending a text msg, here is how (taken from post 28 at
http://www.modaco.com/content-page/251138/message-sent-notification-sound/page/20/):
HOW TO DISABLE THE “DING” NOTIFICATION SOUND FOR SENT SMS
1. Install a registry editor like
Resco File Explorer’s add-on registry editor or
PHM registry editor.
2. Open HKEY_CURRENT_USER
3. Tap control panel>notifications
4. Tap default
5. Tap options
6. Choose what value will be applicable to you and replace the default number with it (for HTC Diamond, the number was 13, I replaced it with 8 to suit my preference):
0 – show icon
1 – show icon and play notification sound
2 – show icon and vibration
3 – show icon and vibration and play notification sound
4 – same as 0
5 – same as 1
6 – same as 3
7 – same as 3
8 – show icon and notification bubble
9 – show icon and play notification sound and show notification bubble
10 – show icon and notification bubble and vibration
7. If you want to configure how long the notification bubble will stay on the screen, tap on duration instead of options. Change the number there into the number of seconds you want the notification bubble to stay up.