The blank image in IE is most likely from a typo in setting up the images. If you have a link to your page, I'll peek at the source and see if there's a problem.
Getting linked images to expand to the size of your iframe is simple (if tedious). Give each full-sized image its own basic page, setting the width and height in the <img src="fullsize.jpg"....> tag to match your iframe. Then link to those pages, instead of directly linking to the images.