I think what you are talking about is something I just committed to 1.5 not the feature that this thread references, maybe.

In which case, actually I think groups shouldn't be imported (as you can never select to import users, or user files or user data) but I guess you're not shown that maybe. I'm about to go off to MoodleMoot but I'll have a look when I get back. Can you file a bug report please?

Penny