The matrix jobs created via 1.471 version are not working anymore.

During jenkins boot-up the following error messages can be found in the jenkins.log

SEVERE: Failed Loading job website-acceptance-test-suite
java.lang.NullPointerException
at hudson.matrix.MatrixProject.updateTransientActions(MatrixProject.java:431)
at hudson.model.AbstractProject.onLoad(AbstractProject.java:296)
at hudson.matrix.MatrixProject.onLoad(MatrixProject.java:466)
at hudson.model.Items.load(Items.java:115)
at jenkins.model.Jenkins$17.run(Jenkins.java:2492)
at org.jvnet.hudson.reactor.TaskGraphBuilder$TaskImpl.run(TaskGraphBuilder.java:146)
at org.jvnet.hudson.reactor.Reactor.runTask(Reactor.java:259)
at jenkins.model.Jenkins$7.runTask(Jenkins.java:878)
at org.jvnet.hudson.reactor.Reactor$2.run(Reactor.java:187)
at org.jvnet.hudson.reactor.Reactor$Node.run(Reactor.java:94)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:662)

Perhaps it's something with the new Matrix job feature?