SharePoint 2010 PerformancePoint Services errors

I'm getting the same two Event Log errors repeating once every hour.  The errors occur on a Windows 2008 R2 64-bit server running SharePoint 2010 SP1.  Anybody have any suggestions to how to fix these errors?

Log Name:      Application
Source:        Microsoft-SharePoint Products-PerformancePoint Service
Date:          12/20/2013 11:47:40 AM
Event ID:      4
Task Category: PerformancePoint Services
Level:         Error
Keywords:      
User:          xxxxxxxxxx
Computer:      xxxxxxxxxx
Description:
An unexpected error occurred.  Error 58536.
Exception details:
System.InvalidOperationException: Operation is not valid due to the current state of the object.
   at Microsoft.PerformancePoint.Scorecards.ServerCommon.ServerUtils.set_UnauthorizedAccessDetected(Boolean value)
   at Microsoft.PerformancePoint.Scorecards.BIMonitoringServiceApplicationProxy.HandleChannelException(Exception ex, SPServiceLoadBalancerContext loadBalancerContext)
   at Microsoft.PerformancePoint.Scorecards.BIMonitoringServiceApplicationProxy.ExecuteOnChannel(CodeBlock codeBlock)


Log Name:      Application
Source:        Microsoft-SharePoint Products-PerformancePoint Service
Date:          12/20/2013 11:47:40 AM
Event ID:      1
Task Category: PerformancePoint Services
Level:         Error
Keywords:      
User:          xxxxxxxxxx
Computer:      xxxxxxxxxx
Description:
Failed to execute SharePoint BI Maintenance Job
Microsoft.PerformancePoint.Scorecards.BpmException: An unexpected error occurred.  Error 58536.  Additional details have been logged for your administrator.
   at Microsoft.PerformancePoint.Scorecards.BIMonitoringServiceApplicationProxy.ExecuteOnChannel(CodeBlock codeBlock)
   at Microsoft.PerformancePoint.Scorecards.BIMaintenanceJob.Execute(Guid targetInstanceId)