Is this SVG being used in an HTML file by itself? If so, don't try to vertically center the content that way. The easiest way to do what you're trying to do is to set the height and width of everything to 100% and stuff it in the HTML. For example:
Code:
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xmlns:svg="http://www.w3.org/2000/svg">
<head>
<title>Title page</title>
<link rel="stylesheet" type="text/css" href="nookstyles.css" />
<link rel="stylesheet" type="text/css" href="nookstyles2.css" />
<style type="text/css">
html,body {
height: 100% !important;
width: 100% !important;
margin: 0 !important;
border-width: 0 !important;
padding: 0 !important;
}
</style>
</head>
<body style="height: 100%; width: 100%;" >
<div style="width: 100%; height: 100%;">
<!-- Created with Inkscape (http://www.inkscape.org/) -->
<svg
xmlns:svg="http://www.w3.org/2000/svg"
xmlns="http://www.w3.org/2000/svg"
version="1.1"
width="100%"
height="100%"
id="svg2"
xml:space="preserve" viewBox="0 0 395.22656 688.82343" preserveAspectRatio="xMidYMid"><metadata
id="metadata8"></metadata><defs
id="defs6" /><g
transform="matrix(1.25,0,0,-1.25,0,688.82344)"
id="g10"><g
transform="translate(72,477)"
id="g12"><text
transform="matrix(1,0,0,-1,-37.57,-83.26)"
id="text14"><tspan
x="0 43.327873 74.9673 93.238899 117.6906 134.01413 172.10236 190.37395 225.30495"
y="0"
id="tspan16"
style="font-size:67.17500305px;font-variant:normal;font-weight:normal;writing-mode:lr-tb;fill-opacity:1;fill-rule:nonzero;stroke:none" class="useFont_FinalFrontier">Patriots:</tspan></text>
<text
transform="matrix(1,0,0,-1,-22.32,-123.72)"
id="text18"><tspan
x="0 26.097876 44.134632 60.794281 88.638733 96.800613 113.46027 130.92603 139.35661 157.09108 168.74611 187.75693"
y="0"
id="tspan20"
style="font-size:33.58800125px;font-variant:normal;font-weight:normal;writing-mode:lr-tb;fill-opacity:1;fill-rule:nonzero;stroke:none" class="useFont_FinalFrontier">Enemies From</tspan><tspan
x="60.369999 93.75647 101.88477 111.02071 129.05746 137.18576"
y="40.450001"
id="tspan22"
style="font-size:33.58800125px;font-variant:normal;font-weight:normal;writing-mode:lr-tb;fill-opacity:1;fill-rule:nonzero;stroke:none" class="useFont_FinalFrontier">Within</tspan></text>
<text
transform="matrix(1,0,0,-1,40.18,-268.69)"
id="text24"><tspan
x="0 21.16044 31.681881 42.791111 51.980228 61.698357 66.459457 71.377296 82.192635"
y="0"
id="tspan26"
style="font-size:19.59300041px;font-variant:normal;font-weight:normal;writing-mode:lr-tb;fill-opacity:1;fill-rule:nonzero;stroke:none" class="useFont_FinalFrontier">Anovel by</tspan><tspan
x="-34.610001 -18.563334 -9.3350296 -0.145913 4.6151862 15.430522 20.348366 37.335495 43.389732 48.307575 63.257034 72.504929 77.834229 92.195892 103.32472 114.43395"
y="23.6"
id="tspan28"
style="font-size:19.59300041px;font-variant:normal;font-weight:normal;writing-mode:lr-tb;fill-opacity:1;fill-rule:nonzero;stroke:none" class="useFont_FinalFrontier">David A. Gatwood</tspan></text>
<text
transform="matrix(1,0,0,-1,-34.92,-381.8)"
id="text30"><tspan
x="0 9.7989101 16.940275 23.892715 29.308565 33.905739 36.966324 43.918766 50.682281"
y="0"
id="tspan32"
style="font-size:12.59500027px;font-variant:normal;font-weight:normal;writing-mode:lr-tb;fill-opacity:1;fill-rule:nonzero;stroke:none" class="useFont_FinalFrontier">Copyright</tspan></text>
<text
transform="matrix(1,0,0,-1,22,-381.8)"
id="text34"><tspan
x="0"
y="0"
id="tspan36"
style="font-size:12.59500027px;font-variant:normal;writing-mode:lr-tb;fill-opacity:1;fill-rule:nonzero;stroke:none" class="useFont_FinalFrontierCopyright">©</tspan></text>
<text
transform="matrix(1,0,0,-1,36.85,-381.8)"
id="text38"><tspan
x="0 6.6501598 14.43387 22.230175 29.018881 34.019096 40.68185 48.478153 52.571529 59.234283 62.39563 72.710938 78.655777 84.550232 87.610817 94.563263 97.724602 108.64447 112.53632 115.69767 125.30766 131.2525 134.67833 143.92307 151.06442 158.2058 165.15823"
y="0"
id="tspan40"
style="font-size:12.59500027px;font-variant:normal;font-weight:normal;writing-mode:lr-tb;fill-opacity:1;fill-rule:nonzero;stroke:none" class="useFont_FinalFrontier">2003-2012 David A. Gatwood.</tspan><tspan
x="-9.4499998 1.00385 4.064435 7.12502 10.27377 19.99711 23.057695 30.010136 36.773651 40.19949 46.74889 49.910236 59.872879 66.120003 72.669403 78.903923 83.727814 89.634865 95.881989 102.83443"
y="15.18"
id="tspan42"
style="font-size:12.59500027px;font-variant:normal;font-weight:normal;writing-mode:lr-tb;fill-opacity:1;fill-rule:nonzero;stroke:none" class="useFont_FinalFrontier">All Rights Reserved.</tspan></text>
</g></g></svg></div>
</body>
</html>