Having a similar issue to the one discussed in this thread. My background images are functioning properly on all browsers except for versions lower than IE10. After reading through that post, I created a background image in SVG format specifically for IE10. However, I am unsure of how to apply this to my CSS.
CSS
.bg-secondary {
background: url(../img/design/bg-secondary.jpg) no-repeat top center;
-webkit-background-size: 100% auto;
-moz-background-size: 100% auto;
-o-background-size: 100% auto;
background-size: 100% auto;
min-height: 605px;
filter: progid:DXImageTransform.Microsoft.AlphaImageLoader(src='../img/design/bg-secondary.svg', sizingMethod='scale');
}