I have seen my URL's and links failing, due to missing UTF-8 support. Also, every upgrade of JIRA og Confluence replaces server.xml (but not setenv.sh)
The Connector
Add URIEncoding="UTF-8" to the Connector as in:
<Connector className="org.apache.coyote.tomcat4.CoyoteConnector" port="80" address="77.243.52.139" minProcessors="5" maxProcessors="75" enableLookups="false" redirectPort="8443" acceptCount="10" debug="0" connectionTimeout="20000" useURIValidationHack="false" URIEncoding="UTF-8"/>
The Java VM
Add -Dfile.encoding=UTF-8 to the JAVA_OPTS as in:
JAVA_OPTS="-Xms1024m -Xmx1024m -XX:MaxPermSize=512m $JAVA_OPTS -Djava.awt.headless=true -XX:NewSize=512m -Dfile.encoding=UTF-8"
On windows (nooo!) is might be adding -Dfile.encoding=ISO-8859-1