Huhm, after rechecking, here is the problem:

See black-white-wooden-hanger-c-66_73? I bet you have more than 1 cat/product with this name black-white-wooden-hanger, in these cases ssu can only remove the identifier from 1 of those because otherwise it will get all confused and your links all pointing to the wrong location.

If you want, you can manually set alias for these special categories via alias manager, but you MUST make sure you give each cat a unique alias such as black-white-wooden-hanger-blah, and black-white-wooden-hanger-bluh,......

And then clear cache,