Lag on window move

[Naps62]

I'm facing a weird problem. I'm currently using Mint XFCE, although this happened before (with either Cinammon or Gnome, can't really remember which)

Sometimes when i drag any window i have lot's of lag, like it is only moving at 3 Frames per second. But there are 2 twists to this:

- This only happens when dragging with the mouse. Using the touchpad i have no lag at all. I tried moving the windows by both clicking on the title bar, or using the Alt+Scroll-click shortcut.

- Sometimes this happens at not-exactly-random moments. For instance, just now it started happening when i moved my Google Chrome window from the primary monitor to the secondary one. After i moved it back to the first one, the problem stopped, even after moving it again to the second monitor.

Any thoughts?