Your private poi's are stored in /content/userdata/poi
if this folder contains any data, I assume it's the poi's you're looking for.
There is a test you can do:
- Backup (copy to PC) the "save" folder (from root of program),
- Delete the "save" folder, and restart the program.
- You will have to set all settings again, but this can bring back your contacts.
If it does not help, and you need all old settings, you can copy the backed-up "save" folder back to your device, and to create the contacts again