I like it as usual
however, from a code and useability POV you're doing it really, really, REALLY wrong. Having to create another image, then load the effect with JS, making many non necessary HTTP requests (not to mention loading all the images without a preloader to the very least). All that work and unnecessary code could be solved as simple as this:
HTML
Code:
<td class="narrowtd"><!-- EEEW, TABLEZ!1!!! -->
<a href="#"><img class="myimgclass" src="yourimage.jpg" alt="" /></a>
</td>
CSS
Code:
.narrowtd{width:92px; background:#333;}
.myimgclass{width:90px; height:194px; border:1px solid #fff;}
.myimgclass:hover{opacity:.50;-ms-filter:"progid:DXImageTransform.Microsoft.Alpha(Opacity=50)"; filter: alpha(opacity=50);}
and voilá!
btw, I'd try some color change on nav hover, even something subtle would work