Quartz with couple of jobs but only one running - quartz-scheduler

Question

I have quartz schedule with couple of jobs but only one (1st one) is running. Even if I try to force the second job to run it doesn't.
// The Quartz Scheduler
Scheduler scheduler = StdSchedulerFactory.getDefaultScheduler();
JobDetailImpl jobDetail = new JobDetailImpl();
jobDetail.setJobClass(SchedulerJob.class);
jobDetail.setName("4HR");
jobDetail.setGroup("G");
// Initiate CronTrigger with its name and group name
CronTriggerImpl cronTrigger = new CronTriggerImpl();
cronTrigger.setName("4HR");
cronTrigger.setGroup("G");
// setup CronExpression
String CRON_EXPRESSION = "0 0 0/4 * * ?"; // fire every 4 hours
CronExpression cexp = new CronExpression(CRON_EXPRESSION);
// Assign the CronExpression to CronTrigger
cronTrigger.setCronExpression(cexp);
// schedule a job with JobDetail and Trigger
scheduler.scheduleJob(jobDetail, cronTrigger);
JobDetailImpl oneHRJob = new JobDetailImpl();
oneHRJob.setJobClass(Run1HRSchdule.class);
oneHRJob.setName("Job1HR");
oneHRJob.setGroup("G");
CronTriggerImpl oneHRTrigger = new CronTriggerImpl();
oneHRTrigger.setName("Trigger1HR");
oneHRTrigger.setGroup("G");
// Assign the CronExpression to CronTrigger
String CRON_EXPRESSION_1HR = "0 0 0/1 * * ?"; // fire every 1 hour
oneHRTrigger.setCronExpression( new CronExpression(CRON_EXPRESSION_1HR) );
// schedule a job with JobDetail and Trigger
scheduler.scheduleJob(oneHRJob, oneHRTrigger);
// start the scheduler
System.out.println ("Starting Scheduler");
scheduler.start();
System.out.println ("Scheduler started:" + scheduler.isStarted() );
scheduler.triggerJob( oneHRJob.getKey() );
I have tried changing the cron expression but hasn't helped.
What could I be doing wrong?