No help here, but I wanted to note that we’'re also experiencing this problem.
Keeping the thread alive.
Hoping someday someone will at least post a quick-fix to the problem. It’‘s super annoying to our users. The #1 complaint I’'ve gotten with our Wildfire setup.
We’'re running Wildfire v2.6.2 w/ Pandion 2.5
Spark is nice but we really like the Grouped Conversations feature that Pandion uses.