I'm on Windows 7 but experienced this kind of trouble on Vista as well sometimes. When I want to delete a folder when I have previously accessed a subfolder of it, Windows cannot delete it and instead says that I need permissions to do that. I own the files so it can't be that. The problem will usually only go away after I close the Windows Explorer Window in which I viewed the subfolder, or alternatively, I can delete the directory tree manually from the bottom up (because it can delete always delete empty directories.) Now, is there a workaround to that? Some setting or policy to tell windows not to bitch around?
To make it clear whether this is just a problem on my computer, maybe you can also check this: create a directory "A", and create another directory "B" inside it, and maybe create a text file "C.txt" in B. Open C from the explorer, type something, save, close, then click on the little "reduce" arrow sign next to A in the tree view, and then click on A and delete it. That doesn't work for me.