Hive.CompactHive() Access is denied

[Nick]

Current Date/Time: 08-12-2009 12:51:44
Exec. Date/Time: 08-12-2009 12:30:43
Build Date: 01-12-2009
OS: Microsoft Windows NT 5.1.2600 Service Pack 3
Language: pt-PT
System Uptime: 0 Days 3 Hours 23 Mins 28 Secs
Program Uptime: 00:00:50
PID: 4204
Executable: C:\Program Files\Little Registry Optimizer\Little Registry Optimizer.exe
Process Name: System.Diagnostics.Process (Little Registry Optimizer)
Main Module Name: Little Registry Optimizer.exe
Module Count: 62
Thread Count: 6
Thread ID: 8
Is Admin: True
Is Debugged: False
Version: 0.3
CLR Version: 2.0.50727.3603

Type #0 System.ComponentModel.Win32Exception
NativeErrorCode #0: 5
ErrorCode #0: -2147467259
Message #0: Access is denied
TargetSite #0: Void CompactHive()
Source #0: Little Registry Optimizer

StackTrace:
  at Little_Registry_Optimizer.Hive.CompactHive()
  at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
  at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
  at System.Threading.ThreadHelper.ThreadStart()