Increase display size by Ctrl + mouse wheel up, but it switches back to smaller size randomly (it seems).
I'm using Windows 7 and a Logitech wireless mouse with 27 inch monitor.
E.g., In this forum I Increased the display then entered the thread title, but when I clicked in the message area the display size decreased. Only the left mouse button was used.
I'm also using a Logitech touchpad and the Dragon Naturally Speaking software, but have the same problem with the touchpad off and DNS not running.