I've generated an epub file using the dita4publishers DITA Open Toolkit plugin. When I try to downloa/import it into Stanza on my iPhone I get an Import Failed message which is very obscure as to the real problem ..

Import Failed
Failed to download and import FILENAME.epub: Unable to translate FILENAME.epub for import: Unable to parse OPF data from zip:

I'll do more testing with this to see if this is a fundamental problem with epub files generated with this tool or if there's something special about the content I'm converting.