#760 Delete Failing on Root Folder

I'm gettting intermittent failures on deleting folders using the delete task using NANT .91. This issue continually fails somewhere in the folder structure. It typically fails at the root folder of the path specified by the dir attribute.

<target name="remove-branches-checkout" depends="remove-trunk-checkout">
<delete dir="${local.r2w.clienttools.branches.dir}" />
</target>
Error MEssage:
Cannot delete directory 'c:\rwd\work\report2web\clienttools\trunk'.
The directory is not empty.

[Anonymous]

Here's the trace for another random folder that failed.

C:\rwd\work\report2web\clienttools\build\clienttools_auto.build(6,3):
Cannot delete directory 'c:\rwd\work\report2web\clienttools\trunk\projects\common\vb6\fileconversions\reader\pagemart'.:
NAnt.Core.BuildException: C:\rwd\work\report2web\clienttools\build\clienttools_auto.build(6,3):
Cannot delete directory 'c:\rwd\work\report2web\clienttools\trunk\projects\common\vb6\fileconversions\reader\pagemart'. ---> System.IO.IOException: The directory is not empty.

at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
at System.IO.Directory.DeleteHelper(String fullPath, String userPath, Boolean recursive)
at System.IO.Directory.Delete(String fullPath, String userPath, Boolean recursive)
at System.IO.Directory.Delete(String path)
at NAnt.Core.Tasks.DeleteTask.DeleteDirectory(String path) in C:\cygwin\home\rmboggs\nant\src\NAnt.Core\Tasks\DeleteTask.cs:line 304
at NAnt.Core.Tasks.DeleteTask.RecursiveDeleteDirectory(String path) in C:\cygwin\home\rmboggs\nant\src\NAnt.Core\Tasks\DeleteTask.cs:line 261
--- End of inner exception stack trace ---
at NAnt.Core.Tasks.DeleteTask.RecursiveDeleteDirectory(String path) in C:\cygwin\home\rmboggs\nant\src\NAnt.Core\Tasks\DeleteTask.cs:line 263
at NAnt.Core.Tasks.DeleteTask.ExecuteTask() in C:\cygwin\home\rmboggs\nant\src\NAnt.Core\Tasks\DeleteTask.cs:line 193
at NAnt.Core.Task.Execute() in C:\cygwin\home\rmboggs\nant\src\NAnt.Core\Task.cs:line 186
at NAnt.Core.Target.Execute() in C:\cygwin\home\rmboggs\nant\src\NAnt.Core\Target.cs:line 247
at NAnt.Core.Project.Execute(String targetName, Boolean forceDependencies) in C:\cygwin\home\rmboggs\nant\src\NAnt.Core\Project.cs:line 1031
at NAnt.Core.Project.Execute() in C:\cygwin\home\rmboggs\nant\src\NAnt.Core\Project.cs:line 983
at NAnt.Core.Project.Run() in C:\cygwin\home\rmboggs\nant\src\NAnt.Core\Project.cs:line 1068

[Ryan Boggs]

What files remain when that happens?