I am getting the following error in my logs and I was wondering if anyone had received the same error or new what would cause the error:

AssemblyVersion: -1
PortalID: -1
PortalName:
UserID: -1
UserName:
ActiveTabID: -1
ActiveTabName:
RawURL:
AbsoluteURL:
AbsoluteURLReferrer:
UserAgent:
DefaultDataProvider:
ExceptionGUID:
InnerException: Add failed. Duplicate key value supplied.
FileName:
FileLineNumber: -1
FileColumnNumber: -1
Method:
StackTrace:
Message: System.ArgumentException: Add failed. Duplicate key value supplied. at Microsoft.VisualBasic.Collection.Add(Object Item, String Key, Object Before, Object After) at DotNetNuke.Services.Scheduling.DNNScheduling.Scheduler.CoreScheduler.AddToScheduleQueue(ScheduleHistoryItem objScheduleHistoryItem) at DotNetNuke.Services.Scheduling.DNNScheduling.Scheduler.CoreScheduler.LoadQueueFromTimer() at DotNetNuke.Services.Scheduling.DNNScheduling.Scheduler.CoreScheduler.Start()
Source:
Server Name: IHOSTLLC13

Thanks for any help you can provide!