Note that if you are testing on Windows 8.1 or later a result like this can be caused by the mouse behaviour issues introduced with this version of Windows (see User:Garrett/Troubleshooting/Windows 8.1).
Topic on User talk:AndreyKva
I'm using Windows 10, this is the only game I ever had an issue like this with. Thanks for the input, and thanks for correcting a few mistakes in a my edit.