[Zope] DTML 'objectValues()' problem

I have Zope 2.4.0 on a FreeBSD 4.4 release system. I am trying to use the <dtml-in "objectValues()" > to get the list of files in a directory ( a very common thing to do). But it doesn't work. objectValues() returns nothing at all. In another folder, I managed to write a python script where I called it drom the context object, and it works then, but not in DTML. Now, in a seperate folder, it won't even work in a seperate python script, better yet from a DTML call. This is very frustrating, and I would appreciate any input. Thanks. -Dave