Changes have been made in Git (master):

commit 0c677647ff89005a316e3419cc767154f71d6709
Author: Michael M Slusarz <slusarz@horde.org>
Date:   Tue Jan 17 22:48:25 2012 -0700

     Threading improvements

     [mms] Improved threading performance.
     [mms] Threaded sorts now work in all search mailboxes (Request #9700).
     [mms] Hide deleted now works with threaded mailboxes.

  imp/docs/CHANGES                |    3 +
  imp/lib/Imap/Thread.php         |  182 ------------------------------
  imp/lib/Mailbox.php             |    3 +-
  imp/lib/Mailbox/List.php        |  231 
+++++++++++++++++++++++++++------------
  imp/lib/Mailbox/List/Thread.php |   95 ++++++++++++++++
  imp/lib/Prefs/Sort/Sortpref.php |    1 -
  imp/lib/Search.php              |   44 --------
  imp/lib/Views/ListMessages.php  |   14 ++-
  imp/mailbox-mimp.php            |   23 ++---
  imp/mailbox.php                 |   15 +--
  imp/package.xml                 |    3 +
  imp/thread.php                  |   14 +--
  12 files changed, 291 insertions(+), 337 deletions(-)

http://git.horde.org/horde-git/-/commit/0c677647ff89005a316e3419cc767154f71d6709

Changes have been made in Git (master):

commit a098874a4be4aaecc9826931178588ebef52fdbd
Author: Michael M Slusarz <slusarz@horde.org>
Date:   Tue Jan 17 22:45:39 2012 -0700

     Lock sorting for search mailboxes that can not be guaranteed to 
have a single mailbox

     See Bug #9700

  imp/lib/Mailbox.php             |    4 ++++
  imp/lib/Prefs/Sort/Sortpref.php |    6 +++++-
  imp/lib/Search.php              |   18 ++++++++++++++++--
  3 files changed, 25 insertions(+), 3 deletions(-)

http://git.horde.org/horde-git/-/commit/a098874a4be4aaecc9826931178588ebef52fdbd

To make clear, here is what we currently have:
* Sorting for mailboxes that we can always guarantee will only have 
one mailbox (currently, this is the system built-in search queries: 
dynamic view quicksearch, dynamic view filter search, and traditional 
view basic search)

What we need:
* Thread sorting for ALL search mailboxes.
* Sorting for ALL search mailboxes other than those listed above.

commit a098874a4be4aaecc9826931178588ebef52fdbd
Author: Michael M Slusarz <slusarz@horde.org>
Date:   Tue Jan 17 22:45:39 2012 -0700

     Lock sorting for search mailboxes that can not be guaranteed to 
have a single mailbox

     See Bug #9700

  imp/lib/Mailbox.php             |    4 ++++
  imp/lib/Prefs/Sort/Sortpref.php |    6 +++++-
  imp/lib/Search.php              |   18 ++++++++++++++++--
  3 files changed, 25 insertions(+), 3 deletions(-)

http://git.horde.org/horde-git/-/commit/a098874a4be4aaecc9826931178588ebef52fdbd

Use client-side sorting to sort search results.