The Findbugs Hudson Plugin does not recognize Findbugs-Reports that are generated in a different Build-Folder than target (specified in the pom build->directory).

POM Example (Snippet):
<build>
<directory>.target</directory>
<outputDirectory>.target/classes</outputDirectory>
...
</build>

So the Hudson Findbugs Plugin does not look in .target for a Findbugs-report. If i change directory and outputDirectory to target instead of .target (so to Default) everything works.