The lighting in 1.3.x and 1.4.x vanilla was improved over that in 1.2.5, most obviously demonstrated by placing a torch in an overhead 1x1 space. In 1.2.5 the torch space is darkened, while 1.3.2 and later correctly light the block.
Do we know what mod in FTB has undone this fix?
Do we know what mod in FTB has undone this fix?