SCP upload fails with ERROR: Failed to upload files

Uploading files using the SCP plugin (version 1.3) sometimes fails with strange
exceptions (visible in the console output of the job, nothing to see in the
server's log).

---------------------------------------------
ERROR: Failed to upload files

at com.jcraft.jsch.ChannelSftp.stat(Unknown Source)
at be.certipost.hudson.plugin.SCPSite.upload(SCPSite.java:142)
at
be.certipost.hudson.plugin.SCPRepositoryPublisher.perform(SCPRepositoryPublisher.java:106)
at
hudson.tasks.BuildStepCompatibilityLayer.perform(BuildStepCompatibilityLayer.java:33)
at
hudson.model.AbstractBuild$AbstractRunner.performAllBuildStep(AbstractBuild.java:273)
at
hudson.model.AbstractBuild$AbstractRunner.performAllBuildStep(AbstractBuild.java:261)
at hudson.model.Build$RunnerImpl.post2(Build.java:136)
at hudson.model.AbstractBuild$AbstractRunner.post(AbstractBuild.java:246)
at hudson.model.Run.run(Run.java:677)
at hudson.model.Build.run(Build.java:101)
at hudson.model.ResourceController.execute(ResourceController.java:70)
at hudson.model.Executor.run(Executor.java:65)
---------------------------------------------
ERROR: Failed to upload files
Success
at com.jcraft.jsch.ChannelSftp.throwStatusError(Unknown Source)
at com.jcraft.jsch.ChannelSftp.stat(Unknown Source)
at be.certipost.hudson.plugin.SCPSite.upload(SCPSite.java:142)
at
be.certipost.hudson.plugin.SCPRepositoryPublisher.perform(SCPRepositoryPublisher.java:106)
at
hudson.tasks.BuildStepCompatibilityLayer.perform(BuildStepCompatibilityLayer.java:33)
at
hudson.model.AbstractBuild$AbstractRunner.performAllBuildStep(AbstractBuild.java:273)
at
hudson.model.AbstractBuild$AbstractRunner.performAllBuildStep(AbstractBuild.java:261)
at hudson.model.Build$RunnerImpl.post2(Build.java:136)
at hudson.model.AbstractBuild$AbstractRunner.post(AbstractBuild.java:246)
at hudson.model.Run.run(Run.java:677)
at hudson.model.Build.run(Build.java:101)
at hudson.model.ResourceController.execute(ResourceController.java:70)
at hudson.model.Executor.run(Executor.java:65)
---------------------------------------------

The exceptions happen from time to time - leaving the build as "UNSTABLE".
Usually a rebuild fixes it.