build config history getting spammed

[Bailey, Darragh]

I have a jenkins instance with the build config history plugin installed 
and it appears to be spammed by every build due to a line being 
successively added and then removed from the build config xml.

Here's the snipet from the end of a build config:

<buildWrappers>
   <hudson.plugins.build__timeout.BuildTimeoutWrapper>
     <timeoutMinutes>60</timeoutMinutes>
     <failBuild>false</failBuild>
   </hudson.plugins.build__timeout.BuildTimeoutWrapper>
   <org.jvnet.hudson.plugins.exclusion.IdAllocator>
     <ids>
       <org.jvnet.hudson.plugins.exclusion.DefaultIdType>
         <name>VM1FUNCTESTS</name>
       </org.jvnet.hudson.plugins.exclusion.DefaultIdType>
     </ids>
   </org.jvnet.hudson.plugins.exclusion.IdAllocator>
 
<org.jenkinsci.plugins.envinject.EnvInjectListener_-JobSetupEnvironmentWrapper/>
</buildWrappers>


The line 
<org.jenkinsci.plugins.envinject.EnvInjectListener_-JobSetupEnvironmentWrapper/>
 
gets added and successively removed on each run. i.e. it appears in an 
entry in the build config history shortly after run 1, and then shortly 
after run 2, a config is saved with the line removed. All changes are 
recorded as being made by the SYSTEM user.

The envinject plugin is getting used, there is an entry at the top of 
the job config defining some environment properties to use.

Any ideas as to what's going on?

-- 
Regards,
Darragh Bailey