I am using PMD Plugin (based on findbugs) and Compiler warnings plugin.
When I drill down in the report to the file itself it gives:

Can't read file:
/opt/hudsonslave/workspace/cwswip-l/cws/repos/cws/Synchronizer/synchronizer_DT/java/com/cordys/cws/synchronize/state/item/collection/CwsItemPreparationList.java
(No such file or directory)

We have a distributed setup. The Hudson master only monitors all builds. The
slaves do the actual build. Maybe the plugin tries to read the file locally?
On slave this file exists.

We have installed:
findbugs 2.6
warnings 1.3
pmd 1.3