Windows Scripting VBS: fso.deleteFolder error 800a0046 - permission denied

I have written a very simple script that looks for a certain folder name on our server, verifies it is the target and then deletes it.  It all works fine except for the actual delete statement.  The script is:

' This script runs through every directory below the path specified as Root and deletes all folders with the path ..\AppData\Internet\History.
' It should be scheduled to run once a week on a Connect 2.4 server to keep the internet temporary files under control.
' Written by Jamie Kirkpatrick - Network Administrator, ex7103

'Set the initial variables
dim rootPath, fso, ws, logFile,
'Insert the root path here - this should be the Users folder on the server.
rootPath = "D:\Users"
'Create the FileSystem Object
Set fso = CreateObject("Scripting.FileSystemObject")
'Create a Shell object for user interaction
set ws = WScript.CreateObject("WScript.Shell")

call initiateLog
'Begin stepping through the tree
stepThroughTree ( rootPath )
call cleanUp

sub cleanUp
      logFile.writeLine ("Cleanup finished at : " & now ())
      logFile.close
      set fso = nothing
      set ws = nothing
end sub

Function stepThroughTree ( folder )
      Dim folderList, item, folderObj, deleteTarget
      Set folderObj = fso.GetFolder( folder )
      Set folderList = folderObj.SubFolders
      For Each item In folderList
            If isTarget (item) Then
                  'Delete the folder
                  logFile.write ("Deleting the folder: " & item.ParentFolder.Path & "...")
                  deleteTarget = item.ParentFolder.path
                  fso.deleteFolder ( deleteTarget, true )
                   'Log the deletion
                   logFile.writeLine ("OK")
            Else
                  stepThroughTree ( item )
            End If
      Next
End Function

' Function to check that the folder is a \AppData\Internet\History
Function isTarget ( item )
      if ((item.name = "History") and (item.ParentFolder.Name = "Internet") and (item.ParentFolder.ParentFolder.Name = "AppData")) then
            isTarget = True
      end if
End Function

' Subroutine to check if the correct directory structure eists for logging, and to create a new logfile
Sub initiateLog
      ' Intitiate variables
      dim systemLogs, logFileName, logPath
      Const ForWriting = 2
      'Check whether the log folder exists > if not create it
      if not fso.folderexists ("C:\WINNT\system32\LogFiles\cleanupScripts") then
            set systemLogs = fso.createfolder ("C:\WINNT\system32\LogFiles\cleanupScripts")
      end if
      'Create a new log file for the day
      logFileName = date()
      logFileName = replace (logFileName,"/","-")
      logPath = "C:\WINNT\system32\LogFiles\cleanupScripts\" & logFileName & ".log"
      Set logFile = fso.OpenTextFile(logPath, ForWriting, True)
      'Write some intiation lines to the log
      logFile.writeLine ("Cleaning the Internet folders from user areas.")
      logFile.writeLine ("Process began: "& now())
end sub

I have tried various ideas, and have scoured the internet for answers to this problem, but the trouble with most of them is that they invariably relate to asp.  this is not asp, it is only vbs.  

so here is what i have tried:
1: chaging the path of the target so it has a trailing slash                   deleteTarget = item.ParentFolder.path & "\"
fso.deleteFolder ( deleteTarget, true )
I have tried two slashes as that has also been suggested in some workarounds.
2: using different delete methods.  IE referecing an object's delete method by opening the folder as an object reference and using folder.delete
3: as you can see i have used the force option of the function.
4: I wrote a stripped down script with just the trouble sections in and it still fails:
'Create the FileSystem Object
Set fso = CreateObject("Scripting.FileSystemObject")
deleteTarget = "C:\targetfolder\deleteme"
fso.deleteFolder ( deleteTarget, true
5: Enabling auditing on the folder i am trying to delete - this doesnt seem to show any failures.
6: Using filemon to monitor the access atempt. This crashed the server twice.  

Long and the short is - im lost and it seems ridiculous that esuch a basic scripting function should cause such trouble.  oh yeah - i suppose the server details would help.
its a straight nt 4 server sp6a

thanks in advance.

jamie