Yes, seems that many people having problem about whatsapp database file.
I tried to open whatsapp db file with sqlite manager, but useless because it is encrypted db.
In my opinion, WhatsApp messages is stored in whatsapp server so it will be useless if you tying to look for messagestore.db files in your handphone or Blackberry.
In otherwords, whatsapp server is keeping archive of your whatsapp chat.
I already search google how to open messagestore.db