Shipping method edit links break when machine name includes an underscore (_)

If you define a hook_menu item like admin/commerce/config/shipping/methods/mymodule_mymethod/edit the edit link won't show. If you rename it so that it doesn't contain an underscore, it works. So, admin/commerce/config/shipping/methods/mymodule-mymethod/edit works as would admin/commerce/config/shipping/methods/mymodulemymethod/edit.

I don't know if this is a bug or something that just needs to be documented better.

It appears that the problem occurs on account of $arg = ($type == 'methods') ? strtr($name, '_', '-') : strtr($method . '-' . $name, '_', '-'); inside of commerce_shipping_ui.admin.inc