Creating topics within a Group is FIXED! Answered
Since Friday, 19 Dec 2008, or possibly earlier, the [+ New Topic] action within Groups has been broken. Creating a posting using that method "works," but the topic only appears in the "category" forum you selected via pulldown menus.
I've reported the problem to Rachel, but repairs may take a bit of extra time because of the holidays.
As of Monday 22 Dec 2008, the bug is still present, as noted by Goodhart.
As of Thursday 9 Jan 2009, and following the server update, the bug is still present.
As of Thursday 22 Jan 2009, the bug is still present. :-(
CONCLUSION: This bug was fixed on 28 Jan 2009, as part of the "Answers Release".