With the release of Windows 8.1 you can now set multiple DPI settings on a computer. Each attached screen can have a different DPI and this causes some strange behavior in some recordings.
If you notice that you have black boarders around your video, or the screen seems to be moved to the side of what you intended to record, please try the following;
1) Right click on your Desktop and choose Personalize:
2) In the next window, please click on the Display button in the bottom left corner:
3) On the window that opens up, please check the box that says "Let me choose one Scaling level for all my displays"
After that please restart the computer and then do another short sample recording to see if that clears up the issue.