I can see what you mean. In Firefox the Home link is a few px lower so that it only has one or two px height to click above the other.htm link below it.
I tried to raise the Home link by changing the coordinates to 726,190,757,224 but it refused to go up. Why won't it move up? I found out eventually.
If you give a background-color to the div containing the link to Annthronein which is just above the Home link you will see that it cuts across the Home image map link and Firefox must be a little more affected than IE:
<div style="position: absolute; top: 45px; left: 384px; width:
420px; height: 175px; background-color: skyblue;">
If you raise this div a bit it will clear the image map Home link:-
<div style="position: absolute; top: 40px; left: 384px; width:
420px; height: 175px; background-color: skyblue;">
Leave the coordinates as you had them:-
<area shape="rect" alt="home" coords="726,209,757,224"
href="/index.htm">
I thought at first that your code for coordinates was wrong.
The top left normally has two numbers separated by a comma, then the last pair separated by a comma but no comma between the pairs (which you have) but correcting this made no difference and it didn't explain why the other coordinates work properly.
Code downloaded to my PC will be deleted in due course.
WIN7; IE9, Firefox, Opera, Chrome and Safari for Windows; screen resolution usually 1366*768.
Also IE6 on W98 with 800*600 and IE8 on Vista 1440*900.