Looks like fullscreen mode is the culprit. What worked for me was this:
Go to %appdata%/Guild Wars 2/ folder
Move Local.dat to your desktop
Launch GW2 (it will rebuild Local.dat)
Exit the launcher
Copy Local.dat from your desktop back into the original folder (overwrite the new one that was created)
Launch GW2 again
You will need to configure graphic/sound settings again and when you do use WINDOWED mode
You can also just delete Local.dat, but you lose all of your saved login info, nicknames, etc.