Hi,
I’m having the same problem, but it didn’t start immediately after upgrading to 3.3, it just started on 1/11/2012. We also have the Duplicate Post Checker installed.
Running the diagnostic log shows no errors, and there should be about 100 new posts being written to the database, but there are none.
We are able to post directly to the database.
Feed WordPress version 2011.1019.
Thanks for your help, Laurel ??