The GO SMS Pro messaging app is a cool application as it lets you customize your text messaging functionality from selecting theme, font color, font type, notifications, SMS cloud backup, and security tools like the Private Box. I decided to update this post which was written initially, sometime in July 2012. Back then, accessing the Go SMS Pro Private Box is such a pain. Upon accessing Private Box it would lead you to a prompt for the passcode key but not allowing you to manage the Private Box screen. Indeed it is as if a never-ending loop. But then I realized that this problem happens with old version of Go SMS Pro.
So after so many updates that took place on GO SMS Pro, the settings should look like below:
There you go, hope this helps you in managing your Private Box from GO SMS Pro. If for whatever reason your private box is acting up, try to reinstall the GO SMS Pro app. I hope this gives you insights on how you would troubleshoot your mobile phones to get to the Private Box view, once you get there, the next steps would be easy.