[Zope] <dtml-call >

Hi, What is the difference between <dtml-call "...."> and <dtml-call ...>. For instance, if I have this directory structure: | +-base +-subfolder from base, <dtml-call subfolder.manage_addFolder(...)> doesn't add any folders, while <dtml-call "subfolder.manage_addFolder(...)"> behaves as expected. It took about an hour of experimenting before getting this right. Could someone explain what is the difference here? Thanks. Chui