Actually, IE doesn't recognize image scaling from WordPress. Nothing to do with PageLines.
If you have added, for example, a 500px wide image as the post's feature image (tor the thumbnail), IE probably won't recognize that WordPress has cropped or scaled the image to 150px by 150px. It may decide to display the full-sized image. Similarly, if you're using a very large image in the post's content, and scaling it down (which WordPress does pretty well), IE won't recognize the set size, only the original size, causing the image (in either case) to bleed past any container it sits in, making it (usually) sit behind or under other content.
It's one of the most annoying things I've found about IE. The only cure for it, unfortunately, is to resize images to the specific sizes you want them to be using a graphics editor like Adobe Photoshop, and replacing them. This is tedious, troublesome, time-consuming and to say the least, laborious. But, it is the only sure-fire way of making it work.