Dein Beispiel funktioniert bei mir einwandfrei, es erscheint einfach "," zwischen den Zahlen.
In deinem Code habe ich trotzdem ein paar Sachen angemerkt:
%BRAUCHTS NICHT %\NeedsTeXFormat{LaTeX2e}[1995/06/01]
\documentclass[
BCOR12mm,
DIV18,
headsepline,
oneside,
idxtotoc,
bibtotoc,
liststotoc,
openany,
pointlessnumbers,
12pt
]
{scrbook}
\usepackage[ngerman]{babel}
\usepackage[T1]{fontenc}
\usepackage[latin1]{inputenc}
\usepackage[babel,german=quotes]{csquotes}
\usepackage{lmodern}
\usepackage{float}
\restylefloat{figure} %für \begin{figure}[H]
\usepackage{setspace}
\usepackage{mathcomp}
%WEGLASSEN! %\usepackage{ae} % Für PDF-Erstellung
\usepackage[hang]{caption} % mehrzeilige Captions ausrichten
\usepackage[final]{graphicx} % Bilder einbinden
\usepackage{verbatim} % Für Quelltexte u.ä.
\usepackage{cite} % Zitate [1,3,5,7,6] zu [1,2,5-7] zusammengefassen
\usepackage{marvosym} % zur Darstellung des Eurosymbols \EUR
\usepackage{makeidx} % für Erstellung der Indexdatei
\usepackage{ifthen}
\usepackage{miller} % zum Schreiben von Millerschen Indizees
\usepackage{numprint} % zum Formatieren von Zahlen und Zahl und Einheit
\usepackage{hhline} % erweiterte Möglichkeiten der Liniendarstellung
\addto\extrasgerman{\sisetup{locale = DE}}
\usepackage{siunitx}%für SI-Einheiten
\sisetup{
per=frac
,repeatunits = false
,trapambigrange=false
, tophrase = -
,loctolang=DE:ngerman
%,output-decimal-marker=comma
,decimalsymbol=comma
}
\usepackage{amsmath}
\usepackage{subfig} %Bilder nebeneinander
\usepackage{hyperref}% MUSS IN 90% DER FÄLLE ALS ALLERLETZES PAKET GELADEN WERDEN % URL verlinken, bzw. für Formatierung URL Adresse im Literaturverzeichnis
\renewcommand{\sectionmark}[1]{\markright{\thesection\enskip #1}}
\begin{document}
\SI{0,57}{N \per\mm\squared}
\end{document}
Vielleicht liegt es an veralteten Paketen? Stell ein \listfiles noch vor \documentclass{...}, dann werden im .log-file die verwendeten Pakete und Versionen aufgelistet.
Bei mir sieht das mit dem Code oben so aus:
*File List*
scrbook.cls 2009/07/24 v3.04a KOMA-Script document class (book)
scrkbase.sty 2009/07/24 v3.04a KOMA-Script package (KOMA-Script-dependent ba
sics and keyval usage)
scrbase.sty 2009/07/24 v3.04a KOMA-Script package (KOMA-Script-independent
basics and keyval usage)
keyval.sty 1999/03/16 v1.13 key=value parser (DPC)
scrlfile.sty 2009/03/25 v3.03 KOMA-Script package (loading files)
tocbasic.sty 2009/06/08 v3.03b KOMA-Script package (handling toc-files)
scrsize12pt.clo 2009/07/24 v3.04a KOMA-Script font size class option (12pt)
typearea.sty 2009/07/24 v3.04a KOMA-Script package (type area)
babel.sty 2008/07/06 v3.8l The Babel package
ngermanb.ldf 2008/07/06 v2.6n new German support from the babel system
fontenc.sty
t1enc.def 2005/09/27 v1.99g Standard LaTeX file
inputenc.sty 2008/03/30 v1.1d Input encoding file
latin1.def 2008/03/30 v1.1d Input encoding file
csquotes.sty 2009/09/23 v4.4c context-sensitive quotations
etoolbox.sty 2009/08/06 v1.8 e-TeX tools for LaTeX
etex.sty 1998/03/26 v2.0 eTeX basic definition package (PEB)
csquotes.def 2009/09/23 v4.4c csquotes generic definitions
csquotes.cfg 2009/05/30 v4.4 csquotes configuration
lmodern.sty 2009/10/30 v1.6 Latin Modern Fonts
float.sty 2001/11/08 v1.3d Float enhancements (AL)
setspace.sty 2000/12/01 6.7 Contributed and Supported LaTeX2e package
mathcomp.sty 2001/01/07 v0.1f (TBo)
textcomp.sty 2005/09/27 v1.99g Standard LaTeX package
ts1enc.def 2001/06/05 v3.0e (jk/car/fm) Standard LaTeX file
caption.sty 2009/10/09 v3.1k Customizing captions (AR)
caption3.sty 2009/10/09 v3.1k caption3 kernel (AR)
graphicx.sty 1999/02/16 v1.0f Enhanced LaTeX Graphics (DPC,SPQR)
graphics.sty 2009/02/05 v1.0o Standard LaTeX Graphics (DPC,SPQR)
trig.sty 1999/03/16 v1.09 sin cos tan (DPC)
graphics.cfg 2009/08/28 v1.8 graphics configuration of TeX Live
pdftex.def 2009/08/25 v0.04m Graphics/color for pdfTeX
verbatim.sty 2003/08/22 v1.5q LaTeX2e package for verbatim enhancements
cite.sty 2009/08/29 v 5.2
marvosym.sty 2006/05/11 v2.1 Martin Vogel's Symbols font definitions
makeidx.sty 2000/03/29 v1.0m Standard LaTeX package
ifthen.sty 2001/05/26 v1.1c Standard LaTeX ifthen package (DPC)
miller.sty 2004/09/20 v1.2 print miller indices
numprint.sty 2008/02/17 v1.38 Print numbers (HH)
array.sty 2008/09/09 v2.4c Tabular extension package (FMi)
hhline.sty 1994/05/23 v2.03 Table rule package (DPC)
siunitx.sty 2009/09/21 v1.3a A comprehensive (SI) units package
xkeyval.sty 2008/08/13 v2.6a package option processing (HA)
xkeyval.tex 2008/08/13 v2.6a key=value parser (HA)
amstext.sty 2000/06/29 v2.01
amsgen.sty 1999/11/30 v2.0
xspace.sty 2006/05/08 v1.12 Space after command names (DPC,MH)
si-prefix.cfg 2009/09/21 v1.3a siunitx: SI Multiple prefixes
si-named.cfg 2009/09/21 v1.3a siunitx: SI Named units
si-addn.cfg 2009/09/21 v1.3a siunitx: SI Additional units
si-prefixed.cfg 2009/09/21 v1.3a siunitx: SI Prefixed units
si-accepted.cfg 2009/09/21 v1.3a siunitx: SI Accepted units
si-physical.cfg 2009/09/21 v1.3a siunitx: SI Physically-measured units
si-abbr.cfg 2009/09/21 v1.3a siunitx: Abbreviated units
si-DE.cfg 2009/09/21 v1.3a siunitx: Germany locale
amsmath.sty 2000/07/18 v2.13 AMS math features
amsbsy.sty 1999/11/29 v1.2d
amsopn.sty 1999/12/14 v2.01 operator names
subfig.sty 2005/06/28 ver: 1.3 subfig package
hyperref.sty 2009/10/09 v6.79a Hypertext links for LaTeX
ifpdf.sty 2009/04/10 v2.0 Provides the ifpdf switch (HO)
ifvtex.sty 2008/11/04 v1.4 Switches for detecting VTeX and its modes (HO)
ifxetex.sty 2009/01/23 v0.5 Provides ifxetex conditional
hycolor.sty 2009/10/02 v1.5 Code for color options of hyperref/bookmark (HO
)
xcolor-patch.sty 2009/10/02 xcolor patch
pd1enc.def 2009/10/09 v6.79a Hyperref: PDFDocEncoding definition (HO)
etexcmds.sty 2007/12/12 v1.2 Prefix for e-TeX command names (HO)
infwarerr.sty 2007/09/09 v1.2 Providing info/warning/message (HO)
hyperref.cfg 2002/06/06 v1.2 hyperref configuration of TeXLive
kvoptions.sty 2009/08/13 v3.4 Keyval support for LaTeX options (HO)
kvsetkeys.sty 2009/07/30 v1.5 Key value parser with default handler support
(HO)
url.sty 2006/04/12 ver 3.3 Verb mode for urls, etc.
bitset.sty 2007/09/28 v1.0 Data type bit set (HO)
intcalc.sty 2007/09/27 v1.1 Expandable integer calculations (HO)
bigintcalc.sty 2007/11/11 v1.1 Expandable big integer calculations (HO)
pdftexcmds.sty 2009/09/23 v0.6 LuaTeX support for pdfTeX utility functions (
HO)
ifluatex.sty 2009/04/17 v1.2 Provides the ifluatex switch (HO)
ltxcmds.sty 2009/08/05 v1.0 Some LaTeX kernel commands for general use (HO)
atbegshi.sty 2008/07/31 v1.9 At begin shipout hook (HO)
hpdftex.def 2009/10/09 v6.79a Hyperref driver for pdfTeX
ts1cmr.fd 1999/05/25 v2.5h Standard LaTeX font definitions
t1lmr.fd 2009/10/30 v1.6 Font defs for Latin Modern
supp-pdf.mkii
nameref.sty 2007/05/29 v2.31 Cross-referencing by name of section
refcount.sty 2008/08/11 v3.1 Data extraction from references (HO)
Test-3.out
Test-3.out
ot1lmr.fd 2009/10/30 v1.6 Font defs for Latin Modern
omllmm.fd 2009/10/30 v1.6 Font defs for Latin Modern
omslmsy.fd 2009/10/30 v1.6 Font defs for Latin Modern
omxlmex.fd 2009/10/30 v1.6 Font defs for Latin Modern
ot1lmss.fd 2009/10/30 v1.6 Font defs for Latin Modern
ot1lmtt.fd 2009/10/30 v1.6 Font defs for Latin Modern
***********
Mach das mal bei dir und vergleiche die Versionen. Es sind übrigens so viele Pakete, weil du kein wirklich minimales Beispiel gemacht hast.