IE8 - navigation links not working - css

Question

Hey all - I've been googling this as much as possible, but nothing I do seems to help.
I've been working on a website (www.philipdukes.co.uk), and although the nav seems to work fine in FF, Safari, chrome, even IE6 (miraculously), on my system here it fails miserably in IE8: the navigation links don't work.
I hover on them, get the rollover animation, but they're not "clickable". They're basic text links, text-aligned off the screen, and then the area that they represent should be clickable. The image that fills the space isn't the link. If I remove the image I can click the area, and if I remove the text-align I can click the link text (but only the link text).
It's driving me nuts, as its the last thing I need to sort before everythings fully working...
The code for the nav bar is here:
<div class="navHolder">
<div class="nav current-home">
<div id="home"><img src="images/nav/home.png" alt="home." />home.</div>
<div id="bio"><img src="images/nav/bio.png" alt="biography." />biography.</div>
<div id="media"><img src="images/nav/media.png" alt="media." />media.</div>
</div>
<div class="nav2 current-home">
<div id="press"><img src="images/nav/press.png" alt="press." />press.</div>
<div id="pdr"><img src="images/nav/pdr.png" alt="plane dukes rahman trio." />Plane Dukes Rahman Trio.</div>
<div id="contact"><img src="images/nav/contact.png" alt="contact." />contact.</div>
</div>
and the css styling is here (any optimization here is also welcome!):
/*
*
* BEGIN NAV SECTION
*
*/
.navHolder{
position: relative;
width: 100%;
height: 100px;
margin: 0;
padding: 0;
}
.nav, .nav2 {
width: 600px;
height: 50px;
position: relative;
overflow: hidden;
margin: 0 auto;
padding: 0;
top: 0;
}
#home, #bio, #media, #press, #pdr, #contact{
position: absolute;
top: 0px;
overflow: hidden;
width: 200px;
height: 50px;
background: url(images/nav/nav-back.png) 0 0 no-repeat;
}
.nav a, .nav2 a{
position: absolute;
z-index: 100;
display: block;
top: 0px;
height: 50px;
width: 200px;
text-indent: -9000px;
}
.nav img, .nav2 img{
position: relative;
z-index: 50;
width: 200px;
height: 50px;
}
#home, #press{
left: 0;
}
#bio, #pdr{
left: 200px;
}
#media, #contact{
left: 400px;
}
.current-home #home, .current-bio #bio, .current-contact #contact, .current-press #press, .current-pdr #pdr, .current-media #media{
background-position: 0 -246px;
}

Answer 1

You are missing:
.nav a, .nav2 a {
left: 0;
}
That should fix the problem. Always set a vertical (top or bottom) and horizontal (left or right) placement when using position:absolute.
UPDATE
Anytime a background is set, it starts working as expected. Through a lot of testing, you will probably find a different way of fixing the problem. But this is what I would do:
BEST WAY:
Either get rid of the img tags or hide them, and instead apply them as background-image to your a tags.
Change the position on the a tags to relative instead of absolute as they would be the only visible child of the parent div
QUICK WAY
.nav a, .nav 2 { background: url(/images/shim.png) }
Where shim.png is a 8-bit fully transparent, one pixel PNG. A 8-bit PNG shim is smaller than the same dimension (1 pixel) gif, and everything will still work as planned.

Answer 2

Serve the same styles to IE8 that you serve to IE7, and then put the following element in the document head:
<meta http-equiv="X-UA-Compatible" content="IE=EmulateIE7" />
This will make IE8 emulate IE7. Because you are having no issues with IE7, I presume this would work for you.

Answer 3

Not entirely sure what's going on there, but seems to be some kind of problem (maybe an IE8 bug) with the layering of the link and image elements. When I change the z-index of .nav img, .nav2 img to any negative value instead of 50, then the links become clickable.
I'm not sure if that is a practical possibility in this case, though, since the negative z-index might cause the images to no longer be visible.