Darn Ringtones

[Pimpleo]

hey im having issues with my i760 or maybe someone can clarify for me. i have ringtones set for my msgs. i would like for the the ringtones to end when i dismiss the txt msg it is annoying that the phone alerts continues even after i have read or dismissed the txt. can someone plz help me?
other than that i totally like the phone. also i can sync with my computer and does anyone know of any 3rd party sites for applications that are useful to the phone. ex., backup..etc