The documentation for the delete() method of the WindowsRegistry class says that it deletes the key and all of its subkeys. This would only work on Windows 95 / 98 / ME.
From NT on, the API used for this method will only delete the key if it is empty. The API should be changed to SHDeleteKey().
Anonymous
Committed revision 4873.
Committed revision 6170.
4.1.0 merge.
The fix for this item was in the 4.1.0 release.