I have recently purchased Parallels Desktop 12, and I am using it with a Win XP Pro guest OS and MacOS Sierra host OS. All seems to work well, except for one problem with the mouse wheel scrolling. If I scroll the contents of a Windows folder (eg. set to list view), the movement is far too much, to the extent that some of the columns are missed completely. Changing the number of lines per wheel click in the Windows mouse control panel makes no difference. What could be causing this, and is there a solution ? I have tried using the same guest OS under VMWare Fusion, and that doesn't exhibit the same issue, so it isn't a Windows bug.