Empty Finder folders don't display correctly in Mountain Lion

Anyone else experienced this or have a solution?

I upgraded from Lion to Mountain Lion last night (on a late 2010 MacBook Air). Everything went smoothly. But I have an irritating problem with Finder.

When opening folders (from sidebar icons or from main window icons), if the folder contains documents or subfolders Finder displays the contents of the folder correctly.

However if the folder is empty, Finder displays either the contents of the last folder that I looked at that did contain documents, or a strange jumbled mix of icons. These can be selected, but cannot be deleted, opened, viewed, etc.

So, for example, if I open my Documents folder (which has a lot of things in it), Finder displays the contents correctly.

If I then open my Downloads folder (which is empty), Finder either displays the contents of the Documents folder, or a strange mix of icons.

Any suggestions? The only workaround I've found is to set the empty folders to a different type of view (e.g. the detailed list).