Issue in Mail Fetching

We have been seeing a number of issues related to mail fetching since late last week. At this point I get a message every 30 minutes or so as follows:

System Log Message: Issue in eMail Fetching
Probable Cause: Mail fetcing is delayed ....due to start time and finish time is ZERO

I also received one last weeek as follows:

System Log Message: Issue in email fetching
Occured At: Thu May 01 10:15:57 CDT 2008
Probable Cause: Mail fetcing is delayed ....due to schedule time=1209651748010 more than curren sys time=1209654957249, finishTime=1209651568010, startTime=1209651567940, timeToWait=1980000

Any ideas what needs to be done to correct this? I am running build 7011
Thanks