Running the "Confluence - Unit test" on JDK 1.4 fails on the Bamboo instance running on Keg.
It succeeds running it against JDK 1.5.

Running the same tests on the same server, same JDK, same Maven is fine outside of Bamboo...

I ran then using maven debug mode and it seems that with JDK 1.4 configured there are some JDK 1.5 libraries on the classpath which could be the cause of the problem.
http://keg.sydney.atlassian.com:8080/bamboo/build/viewBuildLog.action?buildKey=CONF-MAIN&buildNumber=1717

Here is an extract of the debug trace:

ClassLoader: typeclass sun.misc.Launcher$ExtClassLoader, value=sun.misc.Launcher$ExtClassLoader@18e3e60
10-May-2007 12:19:22 : file:/usr/​java/​jdk1.5.0_07/​jre/​lib/​ext/​dnsns.jar
10-May-2007 12:19:22 : file:/usr/​java/​jdk1.5.0_07/​jre/​lib/​ext/​sunjce_provider.jar
10-May-2007 12:19:22 : file:/usr/​java/​jdk1.5.0_07/​jre/​lib/​ext/​localedata.jar
10-May-2007 12:19:22 : file:/usr/​java/​jdk1.5.0_07/​jre/​lib/​ext/​sunpkcs11.jar
10-May-2007 12:19:22 ClassLoader: typeclass sun.misc.Launcher$AppClassLoader, value=sun.misc.Launcher$AppClassLoader@1a5ab41
10-May-2007 12:19:22 : file:/home/​devuser/​.m2/​repository/​org/​apache/​maven/​surefire/​ surefire-booter/​1.5.3/​surefire-booter-1.5.3.jar
10-May-2007 12:19:22 : file:/opt/​java/​tools/​maven-2.0.4/​core/​plexus-utils-1.1.jar
10-May-2007 12:19:22 ClassLoader: typeclass org.apache.maven.surefire.IsolatedClassLoader, value=org.apache.maven.surefire.IsolatedClassLoader@ab95e6
10-May-2007 12:19:22 : file:/opt/​bamboo/​xml-data/​build-dir/​CONF-MAIN/​confluence/​target/​test-classes/​
10-May-2007 12:19:22 : file:/opt/​bamboo/​xml-data/​build-dir/​CONF-MAIN/​confluence/​target/​classes/​