It is impossible to have an alias called "cd..." where ... is anything or nothing. If you create an alias with a name such as I did, "cdate" then this function will be inaccessible. There is no issue if "cd" are not the first two characters, only if they are.
I am sure that there is a reason for this obscure bug, but without the source I doubt I shall ever know. Please fix this as soon as possible; it is breaking scripts.