I bought a game app (Ferrari GT: Evolution) and installed it two nights ago. Everything was fine yesterday and today until after I played one race on the new app. The only other thing I did was put on an an Invisible Shield front protector last night. There's no phone ring tone, no SMS sound. Several other apps have no sound. The iPod part of this iPhone 3G plays music fine, streaming audio is fine as is the app mentioned above. Anyone else have this problem? Suggestions? I have sound on certain parts, but not with the phone or SMS messages. Thanks for any ideas.