I fixed this problem a while ago, but it came up again in a different form with different source code. The window source is below:
sf::RenderWindow App(sf::VideoMode(800, 600), "Dodger");
App.UseVerticalSync(useVertSync);
App.SetFramerateLimit(frameLimit);
use vert sync is true and framelimit is set to 45. The program runs on an average amount of CPU, but it acts like a program running on 100% CPU (mouse flickers, disappears when you don't move it, boxes appear by mouse, etc.). This started occurring all-of-the-sudden. All of the images move quickly and at a normal pace.