I see the following thing in your template.
the readmore button has an image, that is impossible to be found.
transparent url(images/buttonreadmore.gif) no-repeat scroll 0 0;
this buttonreadmore is not there.
here is what you can do to make the text visible.
open your joomla.css file (should be in your template folder)
change the readon button from this
a.readon {joomla.css (line 319)
background:transparent url(images/buttonreadmore.gif) no-repeat scroll 0 0;
color:#00000;
display:block;
font-size:21px;
font-weight:bold;
height:20px;
margin-top:10px;
text-indent:-5000px;
width:86px;
}
to this
a.readon {
color:#FFFFFF;
display:block;
font-weight:bold;
height:20px;
margin-top:10px;
}
If you want your readon in another color, then you will have to change
color: #FFFFFF; to something else
