Inaccurate Mouse movement in Unity Player / Web Player games

[hintboyright]

In most of the Unity Player/Web Player games I've played (Kerbal Space Program is an exception) the mouse moves at an angle when I move it straight. At slower speeds, the mouse barely moves the direction I intend it to move. Best way to explain this is through a video on a Unity Player game on which this happens. https://www.youtube.com/watch?v=rMFiJNB8MCs

[hintboyright]

Also, any mouse input (LMB up/down, RMB up/down, MMB up/down and scrolling the mouse wheel up or down) moves the mouse by what looks like a pixel to the right then down