The problem is that in css, the classes alpha and omega uses nth-child that not works in IE8 and below :
.alpha, .has-taxonomy-show.singular #content .video-sidebar .video-section .video-item:nth-child(even)
.omega, .has-taxonomy-show.singular #content .video-sidebar .video-section .video-item:nth-child(odd)
you should do this with JQuery just for IE8<