Nvidia or AMD?
EDIT: I don't know when you'll be back online, so I can't hang around hoping you reply. If you happen to have AMD/ATI or whatever, I suggest downloading RadeonPro. I'm not sure if I can post a link, so just google it. Application specific settings not working is a common problem with some of the new drivers, RadeonPro fixes this. It handles just like the Catalyst Control Center, so just add Blockland.exe as an application (not the launcher, I made this mistake originally) and scroll down to force V-Sync.