I am using jQuery.tmpl() to try to render some images. They render but disappear!!!!

plugin works fine for just posting the imageurl, but if i try to use the same value in an img src tag it does something very weird: renders them then erases them.
html
- <div id="viewport">
<!----- picture tiled --->
</div>
CSS
- #viewport {
width: 3000px;
height: 3000px;
background:#6cf;
}
the "template"
- var markup = '${block1} <img src=${block1} class="ba-bg"> ${block2} <img src=${block2} class="ba-bg"><img src=${block3} class="ba-bg"><img src=${block4} class="ba-bg"><img src=${block5} class="ba-bg"><br>'
the call
- $.tmpl( "pngTemplate", toshow )
- .appendTo( "#viewport" );
where "toshow" assembles a json list of images like: block1 = "ice.jpg" , block2 ="sand.jpg", etc,,
Whith the template above all i see is
Notice that the urls for blocks 1 and 2 are showing, as i added them to the template in addition to the img statement. But none of the images are showing!
Page is at
http://www.virtualsoil.com/minecraft/mine_terrain1.html (scroll down and click "render" to get to the part with jQuery.tmpl)
Anyone can help me get my images to show on "viewport" ?