Have the same here, jenkins 1596.2, subversion plugin 2.5 and mulitplescm plugin 0.3.
[bit off-topic: strangely if I upgrade the multiple scm plugin to 0.5 then all the jobs using it are not visible anymore in Jenkins. If I revert then they are visible again]
However, I replicated the very same job on a different installation of Jenkins (same versions: 1596.2, subversion 2.5 and mulitplescm 0.3, later upgraded to 0.5) and it worked fine. I now have the same suspect as Brantone, that existing projects that had already some build are affected by the bug, new projects are not.