I upgraded subversion plugin one or 2 weeks ago

The first time one of our project sources have been updated in SVN, this project is build again and again with the following code change info:

{Started on 25 mai 2012 13:50:49 Workspace doesn't contain https://xxx.yyy.com:443/svn/applications/2011/Telefonica/SelfCareApp/trunk/sources. Need a new build Done. Took 0,2 s Changes found}

This happens with both modes :

• Emulate clean checkout by first deleting unversioned/ignored files
• always check up a fresh copy
  (I even deleted manually the workspace, in both configuration to be sure to avoid any memorizing side-effect of the extracted source code)

It also happens on another single project yesterday after its source has been updated.
All other projects are currently working correctly (ie only rebuilding when the svn source change).

A weird thing is that it is the same user who updated the code in both projects

This issue is similar to the JENKINS-13835 issue but in our case we have more than 12 living builds, only two seems impacted for the moment-