I want to do a 4x6 verticle crop on a horizontal pic

I have a 4x6 horizontal picture. I want to crop it 4x6 vertically. .... resulting in a 4x6 verticle picture.

I've tried to set a custom crop size as 6x4, but iphoto just returns me to the preset 4x6 option.

I've tried rotating the picture to verticle, but that ends up rotating the crop selections to verticle also. .. (If the pic is verticle I would want to horizontal crop in this example).

I could swear that I accidentally drug the 4x6 crop box around enough to where I somehow flipped it to a 6x4 verticle crop box, but I can't for the life of me do it again or figure out how I did it. .. Maybe I dreamed it.

It seems like it should be a simple procedure. Any ideas?

It's iphoto 5.0.4 (263)