You may be wondering why a visitor's post on the Facebook Timeline of the page you're managing just doesn't seem to want to show up in VSocial!
The reason is, most likely, the visitor has configured his/her Facebook profile privacy settings to not let applications access their data. Even through their post is on your Page's timeline and is seemingly "public", Facebook takes privacy seriously, and have provided its users the ability to restrict what data is accessible by Facebook Applications, regardless where the data is placed (whether in their profile or their posts on other Pages).
Official word from Facebook:
Hey, thanks for checking what the story is on this. Yeah, some users opt-out of allowing their info to be shared via the platform. Even though it is publicly visible on our product, we have to respect the user's privacy settings. Apps don't get access to it because that is the intention of the privacy setting. We want users to be able to completely control their information and prevent any third-party app from obtaining their information whether publicly available or not.