Hi,
It's the CSS. However, I did replace the comments.php with the comments.php from the WordPress default theme just to be safe.
In Style.css comment out:
.js_active #main img{
visibility: hidden;
}
This will allow you to see avatars.
In style1.css, style2.css, style3.css, style4.css (depends on your colour scheme) comment out:
#top .entry ul li {
background:transparent url(../images/skin1/bullet1.png) no-repeat scroll 0 9px;
}
This will allow you to see the social login buttons.
I'm not sure what these CSS styles do. I'm still figuring it out but they are the cause.
I would suggest using FireBug to tinker with your CSS.