The violations.hpi relies on xpp3 in hudson. hudson 1.207 does not
have the correct xpp3 (it only has min). violations.hpi should have
it's own xpp3 jar in it's WEB-INF/lib directory.

the console output is:

drwxrwxr-x 4 preilly preilly 4096 2008-04-16 10:41 ..
FATAL: org/xmlpull/v1/XmlPullParserFactory
java.lang.NoClassDefFoundError: org/xmlpull/v1/XmlPullParserFactory
at hudson.plugins.violations.parse.ParseXML.parse(ParseXML.java:40)
at
hudson.plugins.violations.types.findbugs.FindBugsDescriptor.parseMessages(FindBugsDescriptor.java:82)
at
hudson.plugins.violations.types.findbugs.FindBugsDescriptor.parseMessages(FindBugsDescriptor.java:73)
at
hudson.plugins.violations.types.findbugs.FindBugsDescriptor.<clinit>(FindBugsDescriptor.java:68)