can not generate html with xalan

I tried to use xslproc and it worked fine. However, I was trying to 
setup and use xalan. I keep on getting this error:


[mansour@mars 1]$ java org.apache.xalan.xslt.Process  -xsl 
/usr/share/sgml/docbook/xsl-stylesheets/html/docbook.xsl -out 
myFile.html -in article.xml

SystemId Unknown; Line #185; Column #91; XSLT Error 
(javax.xml.transform.TransformerConfigurationException): 
javax.xml.transform.TransformerException: 
javax.xml.transform.TransformerException: 
org.apache.xpath.functions.FuncConcat only allows >1 arguments
Exception in thread "main" java.lang.RuntimeException: 
javax.xml.transform.TransformerException: 
javax.xml.transform.TransformerException: 
org.apache.xpath.functions.FuncConcat only allows >1 arguments
        at org.apache.xalan.xslt.Process.doExit(Process.java:1153)
        at org.apache.xalan.xslt.Process.main(Process.java:1126)


Xalan is installed properly:

[mansour@mars 1]$ java  org.apache.xalan.xslt.EnvironmentCheck
#---- BEGIN writeEnvironmentReport($Revision: 1.29 $): Useful stuff 
found: ----
version.DOM.draftlevel=2.0fd
java.class.path=/opt/jdk/lib/dt.jar:/opt/jdk/lib/jconsole.jar:/opt/jdk/lib/sa-jdi.jar:/opt/jdk/lib/htmlconverter.jar:/opt/jdk/lib/tools.jar:/opt/jdk/lib/:/opt/tomcat/common/lib/servlet-api.jar:.:/opt/J2EE/lib/j2ee.jar:.::/opt/jdk/lib/xml-apis.jar:/opt/jdk/lib/xercesImpl.jar:/opt/jdk/lib/xalan.jar:/opt/jdk/lib/jconsole.jar:/opt/jdk/lib/tools.jar:/opt/jdk/lib/xsltc.jar:/opt/jdk/lib/serializer.jar:/opt/jdk/lib/sa-jdi.jar:/opt/jdk/lib/dt.jar:/opt/jdk/lib/htmlconverter.jar:.::/opt/jdk/lib/xml-apis.jar:/opt/jdk/lib/xercesImpl.jar:/opt/jdk/lib/xalan.jar:/opt/jdk/lib/jconsole.jar:/opt/jdk/lib/tools.jar:/opt/jdk/lib/xsltc.jar:/opt/jdk/lib/serializer.jar:/opt/jdk/lib/sa-jdi.jar:/opt/jdk/lib/dt.jar:/opt/jdk/lib/htmlconverter.jar
version.JAXP=1.1 or higher
java.ext.dirs=/opt/jdk1.6.0_02/jre/lib/ext:/usr/java/packages/lib/ext
version.xerces2=Xerces-J 2.7.1
version.xerces1=not-present
version.xalan2_2=Xalan Java 2.7.0
version.xalan1=not-present
version.ant=not-present
java.version=1.6.0_02
version.DOM=2.0
version.crimson=not-present
sun.boot.class.path=/opt/jdk1.6.0_02/jre/lib/resources.jar:/opt/jdk1.6.0_02/jre/lib/rt.jar:/opt/jdk1.6.0_02/jre/lib/sunrsasign.jar:/opt/jdk1.6.0_02/jre/lib/jsse.jar:/opt/jdk1.6.0_02/jre/lib/jce.jar:/opt/jdk1.6.0_02/jre/lib/charsets.jar:/opt/jdk1.6.0_02/jre/classes
#---- BEGIN Listing XML-related jars in: foundclasses.java.class.path ----
xml-apis.jar-apparent.version=xml-apis.jar from head branch of 
xml-commons, tag: xml-commons-external_1_3_02
xml-apis.jar-path=/opt/jdk/lib/xml-apis.jar
xercesImpl.jar-apparent.version=xercesImpl.jar from Xerces-J-bin.2.7.1
xercesImpl.jar-path=/opt/jdk/lib/xercesImpl.jar
xalan.jar-path=/opt/jdk/lib/xalan.jar
xsltc.jar-apparent.version=xsltc.jar present-unknown-version
xsltc.jar-path=/opt/jdk/lib/xsltc.jar
serializer.jar-apparent.version=serializer.jar present-unknown-version
serializer.jar-path=/opt/jdk/lib/serializer.jar
xml-apis.jar-apparent.version=xml-apis.jar from head branch of 
xml-commons, tag: xml-commons-external_1_3_02
xml-apis.jar-path=/opt/jdk/lib/xml-apis.jar
xercesImpl.jar-apparent.version=xercesImpl.jar from Xerces-J-bin.2.7.1
xercesImpl.jar-path=/opt/jdk/lib/xercesImpl.jar
xalan.jar-path=/opt/jdk/lib/xalan.jar
xsltc.jar-apparent.version=xsltc.jar present-unknown-version
xsltc.jar-path=/opt/jdk/lib/xsltc.jar
serializer.jar-apparent.version=serializer.jar present-unknown-version
serializer.jar-path=/opt/jdk/lib/serializer.jar
#----- END Listing XML-related jars in: foundclasses.java.class.path -----
version.SAX=2.0
version.xalan2x=Xalan Java 2.7.0
#----- END writeEnvironmentReport: Useful properties found: -----
# YAHOO! Your environment seems to be OK.

can someone tell me what's wrong ?