[Zope] dtml-in and maps...

Greetings, This seems like it should be a simple thing.... but I can't seem to find how to make dtml-in behave with maps. In particular, empty maps. I've tried mapping, i've tried testing _.len(map.keys()), and various other things. But it always fails, telling me Error Type: KeyError Error Value: 0 What am I missing? Have a better one, Curtis.