you can use the -ms-filter but i guess its the same issue as opacity if you do filter before -ms-filter it fails se more at:
http://www.quirksmode.org/css/opacity.html for that theory
so you need to do like this:
background-color: #D5D6D7;
background-image: linear-gradient(bottom, rgb(213,214,215) 0%, rgb(251,252,252) 100%);
background-image: -o-linear-gradient(bottom, rgb(213,214,215) 0%, rgb(251,252,252) 100%);
background-image: -moz-linear-gradient(bottom, rgb(213,214,215) 0%, rgb(251,252,252) 100%);
background-image: -webkit-linear-gradient(bottom, rgb(213,214,215) 0%, rgb(251,252,252) 100%);
background-image: -ms-linear-gradient(bottom, rgb(213,214,215) 0%, rgb(251,252,252) 100%);
background-image: -webkit-gradient(
linear,
left bottom,
left top,
color-stop(0, rgb(213,214,215)),
color-stop(1, rgb(251,252,252))
);
-ms-filter: "progid:DXImageTransform.Microsoft.gradient(startColorStr='#D5D6D7',EndColorStr='#FBFCFC')";
filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#D5D6D7', endColorstr='#FBFCFC');
this works for me
besides that you cant have a 8 char hexcode (hex is latin for six) and on top of this you have the same color to gradient between you have to have different colors