Remove Transparent Aero Theme Effect

Thunderbird 5, like Firefox 4 takes advantage of Windows Aero Glass effect on Vista and Windows 7. This results in a transparent menu bar, which some users find this transparency annoying. There are a couple ways to get around this. You can use a Persona or add these lines to your Thunderbird’s userChrome.css file:

/*Removes Transparent Aero Theme Effect Windows Vista & 7 */
window, page, dialog, wizard, prefwindow {
background-color: -moz-Dialog !important; }
#toolbar-menubar {
-moz-appearance: -moz-win-browsertabbar-toolbox !important;
} "