see if you can locate the "new message notification" checkbox inside the GoSMS settings. im not referring to the system settings but the GoSMS settings:
1. open your sms.
2. tap the soft key on the bottom left that opens additional menus.
3. tap settings
4. locate the one i mentioned above.
tell me if it helps
Its easier to ask your brain first before posting (stupid)questions and waiting for (confusing)answers.