Error when running pop email service

Although the pop service seems to be working the log file is full of the following error:

2010-01-21 10:42:56,621 JiraQuartzScheduler_Worker-0 ERROR ServiceRunner Pop [atlassian.jira.service.ServiceRunner] An error occured while trying to run service 'Pop'. Service: Pop id: 10161 is already running!
java.lang.IllegalStateException: Service: Pop id: 10161 is already running!
at com.atlassian.jira.service.JiraServiceContainerImpl.run(JiraServiceContainerImpl.java:56)
at com.atlassian.jira.service.ServiceRunner.execute(ServiceRunner.java:48)
at org.quartz.core.JobRunShell.run(JobRunShell.java:191)
at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:516)