Hovering over an item on the task bar with the mouse cursor should normally give a preview of the target application.
When I mouseover an icon on the taskbar, the thumbnail of available window or windows does appear, but on moving the cursor even a pixel, the preview quickly disappears. This can take anywhere between an instant and a couple of seconds
If the thumbnail does not disappear, it is possible to move the cursor over the thumbnail, something which should normally give a lightbox preview of the application window. This does not happen at all.
The instancy of the disappearance of the thumbnail makes window selection cumbersome and annoying. Far too often, the attempt to click a thumbnail to open the window fails by its sudden vanishing, and I end up clicking something unwanted in the already open window in the background.
Does anyone have any experience, or even better, solution to this problem?