Originariamente inviato da ac_socmel
non usare opacity (se non sai tante altre cose)

codice:
.header {
/* Fallback for web browsers that don't support RGBa */
background-color: rgb(0, 0, 0);
/* RGBa with 0.6 opacity */
background-color: rgba(0, 0, 0, 0.6);
/* For IE 5.5 - 7*/
filter:progidXImageTransform.Microsoft.gradient(startColorstr=#99000000, endColorstr=#99000000);
/* For IE 8*/
-ms-filter: "progidXImageTransform.Microsoft.gradient(startColorstr=#99000000, endColorstr=#99000000)";
}
SIIIIIIII!!!! grazie mille!!!