In the last two days the drop down menus in websites have become problematic. When you click on the down arrow to display the options you cannot click and select - it flashes and goes away. This is with a wireless logitech mouse. The built in mouse on the computer does the same thing. Searches of online forums shows this problem frequently, with no clear solutions. The most common suggestion was a mouse problem, so I tried a plug in mouse, etc. to no avail. What else could it be, and how can it be solved?