[Zope] The id "s5/begin" contains characters illegal in URLs

Hello, I'm trying to rename an object called "s5/Begin" to its lower case counterpart "s5/begin" by using the manage_renameObject () method, but I'm getting the message The id "s5/begin" contains characters illegal in URLs . Any idea what I did wrong here ? My Python script is as follows : ====================== wf = container.GeneralWorkflow catalog = wf.Catalog activities = catalog.ZopeFind (wf, obj_metatypes=['Activity'], search_sub=1) for a in activities: print a[0] wf.manage_renameObject (a[0], a[0].lower()) ====================== Regards, Danny