When a cron job fails once, it is no more executed then

60 r26208

I have defined a cron job that starts every five minutes. It has failed due to a lock that couldn't be taken. (exception below)
Then, it has never been launched again.

2009-05-05 16:10:00,167: INFO [BackgroundJob] - execute Background job ProductionJob_2_0
started @ Tue May 05 16:10:00 CEST 2009
2009-05-05 16:10:00,206: ERROR [BackgroundJob] - Cannot execute job
java.lang.NullPointerException
at org.quartz.SchedulerException.<init>(SchedulerException.java:125)
at org.quartz.JobExecutionException.<init>(JobExecutionException.java:83)
at org.jahia.services.importexport.ProductionJob.failed(ProductionJob.java:140)
at org.jahia.services.importexport.ProductionJob.executeJahiaJob(ProductionJob.java:110)
at org.jahia.services.scheduler.BackgroundJob.execute(BackgroundJob.java:147)
at org.quartz.core.JobRunShell.run(JobRunShell.java:202)
at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:525)
2009-05-05 16:10:00,271: INFO [BackgroundJob] - Background job (of type production) ended with status failed executed in 0s
2009-05-05 16:10:00,370: INFO [JobRunShell] - Job ProductionJob.ProductionJob_2_0 threw a JobExecutionException:
org.quartz.JobExecutionException: java.lang.NullPointerException [See nested exception: java.lang.NullPointerException]
at org.jahia.services.scheduler.BackgroundJob.execute(BackgroundJob.java:157)
at org.quartz.core.JobRunShell.run(JobRunShell.java:202)
at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:525)
Caused by: java.lang.NullPointerException
at org.quartz.SchedulerException.<init>(SchedulerException.java:125)
at org.quartz.JobExecutionException.<init>(JobExecutionException.java:83)
at org.jahia.services.importexport.ProductionJob.failed(ProductionJob.java:140)
at org.jahia.services.importexport.ProductionJob.executeJahiaJob(ProductionJob.java:110)
at org.jahia.services.scheduler.BackgroundJob.execute(BackgroundJob.java:147)
... 2 more