Importing outliner 3 files

[Geoffrey Whittall]

Perhaps I missed it in an earlier discussion, so I have to ask.

Does Omnigraffle 3.1.2 (v70) NOT import Outliner 3.0 (v109) files in their
native format? The files are greyed out in the selection window, and I can't
drop them on the OG icon to open them. Do I have to save them as Outliner 2
files so I can open them in Graffle?
Thanks in advance for any answers.
Geoff