On Tue, Oct 26 2010, Greg Troxel wrote:
  > I don't mean to malign Julien - that commit is surely fine but I haven't
  > bisected the 210 in between.  And I think it's likely gnus is being
  > legal but more aggressive.

  Someone already reported a problem and bissected it to:
  commit aeb7ed491090b5e9e372b6bbd1b2c90c814b6408
  Author: Lars Magne Ingebrigtsen <larsi@quimbies.gnus.org>
  Date:   Sun Oct 24 19:01:16 2010 +0200

      Make internal nnimap moving slightly faster.

  IIRC. Could you check?

Thanks; that motivated me to bisect myself which only took 30 minutes
even with manual testing of each one.

I bisected and ended up doing it twice because the failure is somewhat
random.  I am now pretty confident that gnus at commit is ok for me:

  commit c16f36e878d299b657219ef8f77069a533baf80b
  Author: Lars Magne Ingebrigtsen <larsi@quimbies.gnus.org>
  Date:   Sun Oct 10 15:59:03 2010 +0200

      (nnimap-update-info): Prefer old info over start-article.

and at this one is not:

  commit d94b7a5c0467749d9f4b8273db197992b379ddf7
  Author: Lars Magne Ingebrigtsen <larsi@quimbies.gnus.org>
  Date:   Sun Oct 10 16:32:20 2010 +0200

      (nnimap-update-qresync-info): Finish implementing QRESYNC.


I have not studied the diff yet.