I did it! For those wondering, here's how:
I had both images in one containing div, to which I applied all my positioning styles to orient and size it correctly on the screen. Then I put both images inline, with no divs around them, and gave them both an id (for here i put img1 and img2). Then I gave them these styles:
#img1{
margin: 0px;
padding: 0px;
}
#img2{
position: absolute;
right: 0;
margin-right: 5px;
}
[Edit: trimmed the stylesheet code.] Anyhow, this solution worked perfectly in PC IE,Firefox and Mac IE,Safari,Firefox without any weird margins/padding.
Yay.
__________________Now adding "eh?" to the end of my sentences.