Calibre updated to 0.7.28 | Book Viewer faster, but still needs work

Calibre updated to 0.7.28 | TeleRead: News and views on e-books, libraries, publishing and related topics:

"Update the version of the grahical toolkit (Qt 4.7.1) used in the calibre binary builds on windows and linux. This should result in a significant speed up for the calibre ebook viewer"

Bunch of minor new features updated drivers and bug fixes. The new graphical toolkit does make an appreciable difference with the viewer.
I've been using the book viewer a bit more lately as both the viewer grown more solid and the typical ePub I get my hands on has become more standards compliant.
FYI, here is the custom stylesheet I've grown so far to make reading a little more comfortable. Its a work in progress.

body {
color: white;
background-color:rgb(0,0,125);
text-align:left;
line-spacing:1.4;
margin-top:0px;
margin-bottom:4px;
margin-right:50px;
margin-left:50px;
text-indent:2em;
}
h1, h2, h3, h4, h5, h6 {
color:white;
text-align:center;
font-style:italic;
font-weight:bold;
}
blockquote {text-indent:0em;}
p.tx {text-align:left !important; margin-bottom:.1em !important;margin-top:.1em !important}