New Post: Two Bugs...

The exception occurred at System.Security.Principal.WindowsIdentity.KerbS4ULogon(String upn, SafeAccessTokenHandle& safeTokenHandle)
at System.Security.Principal.WindowsIdentity..ctor(String sUserPrincipalName, String type)
at System.Security.Principal.WindowsIdentity..ctor(String sUserPrincipalName)
at Microsoft.Win32.TaskScheduler.User..ctor(String userName) in C:\Users\dahall\Documents\Visual Studio 2010\Projects\TaskService\User.cs:line 32
at Microsoft.Win32.TaskScheduler.TaskFolder.RegisterTaskDefinition(String Path, TaskDefinition definition, TaskCreation createType, String UserId, String password, TaskLogonType LogonType, String sddl) in C:\Users\dahall\Documents\Visual Studio 2010\Projects\TaskService\TaskFolder.cs:line 409
at Microsoft.Win32.TaskScheduler.TaskFolder.RegisterTaskDefinition(String Path, TaskDefinition definition) in C:\Users\dahall\Documents\Visual Studio 2010\Projects\TaskService\TaskFolder.cs:line 373

and

The exception occurred at Microsoft.Win32.TaskScheduler.V2Interop.ITaskFolder.RegisterTaskDefinition(String Path, ITaskDefinition pDefinition, Int32 flags, Object UserId, Object password, TaskLogonType LogonType, Object sddl)
at Microsoft.Win32.TaskScheduler.TaskFolder.RegisterTaskDefinition(String Path, TaskDefinition definition, TaskCreation createType, String UserId, String password, TaskLogonType LogonType, String sddl) in C:\Users\dahall\Documents\Visual Studio 2010\Projects\TaskService\TaskFolder.cs:line 430
at Microsoft.Win32.TaskScheduler.TaskFolder.RegisterTaskDefinition(String Path, TaskDefinition definition) in C:\Users\dahall\Documents\Visual Studio 2010\Projects\TaskService\TaskFolder.cs:line 373

What triggered this issue was me simply calling RegisterChanges() on an existing task after changing a couple of task settings.