This is the example I have:

Line height does not apply to fluid divs.
Ran into a similar situation not too long ago, did a search and found an article about absolute centering from css-tricks, here is the article and an accompanying fiddle to test it out.
CSS
/* This parent can be any width and height */
.block {
text-align: center;
}
/* The ghost, nudged to maintain perfect centering */
.block:before {
content: '';
display: inline-block;
height: 100%;
vertical-align: middle;
margin-right: -0.25em; /* Adjusts for spacing */
}
/* The element to be centered, can
also be of any width and height */
.centered {
display: inline-block;
vertical-align: middle;
width: 300px;
}
HTML
Some text
But he stole up to us again, and suddenly clapping his hand on my shoulder, said—"Did ye see anything looking like men going towards that ship a while ago?"
Some text
But he stole up to us again, and suddenly clapping his hand on my shoulder, said—"Did ye see anything looking like men going towards that ship a while ago?"
Some text
But he stole up to us again, and suddenly clapping his hand on my shoulder, said—"Did ye see anything looking like men going towards that ship a while ago?"
Demo
http://jsfiddle.net/andresilich/YqKMH/