I was receiving an error when trying to open my inbox.  The error message in webgui.log ended with:

-----------------------------------------------------------------
        LEFT JOIN userProfileData on userProfileData.userId=ibox.sentBy
        
        ORDER BY messageStatus='pending' DESC, dateStamp DESC
        
     : With place holders: .  Root cause: Unknown column 'messageStatus' in 'order clause'
-----------------------------------------------------------------

I made the following change to WebGUI/Inbox.pm and the problem seems to be resolved:

*** Inbox.pm.ek	2009-04-12 23:24:41.000000000 -0500
--- Inbox.pm.orig	2009-04-12 23:17:41.000000000 -0500
***************
*** 363,369 ****
          $sortBy  = qq{ibox.$sortBy};
      }
      else {
!         $sortBy  = q{messageStatus DESC, dateStamp DESC};
          $sortDir = q{};
      }
      
--- 363,369 ----
          $sortBy  = qq{ibox.$sortBy};
      }
      else {
!         $sortBy  = q{messageStatus='pending' DESC, dateStamp DESC};
          $sortDir = q{};
      }