How do I stop the menu from disappearing and reappearing as I move down the list, when the window is smaller than drop-down list?
If the window is smaller than the menu drop-down list and I click on a menu name the list appears and immediately disappears with a faint outline visible. As I move down the list the items appear briefly and then disappear again. Clicking on the location of an item on the list does NOT activate that item.
Alla svar (1)
Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of the extensions is causing the problem (switch to the DEFAULT theme: Firefox (Tools) > Add-ons > Appearance/Themes).
- Don't make any changes on the Safe mode start window.
- https://support.mozilla.com/kb/Safe+Mode
In Firefox 4 and later Safe mode disables extensions and disables hardware acceleration.
- Tools > Options > Advanced > General > Browsing: "Use hardware acceleration when available"
If disabling hardware acceleration works then check if there is an update available for your graphics display driver.