See steps to reproduce. However after restart the groups get expanded, so probably just a problem with the configuration dialog showing bad data.
Steps to Reproduce:
1. Kmail -> Settings -> Appearence -> Message List -> Default Aggregation
3. clone "Current Activity, Threaded"
4. try to set under "Groups & threading": "Group expand policy" to "Always expand groups" or "Expand recent activities"
5. OK dialog
6. Go back to configure the new aggregation type using Configure
7. under Groups & threading there is still "Never Expand Groups"
Aggregation configuration dialog shows always Never expand groups.
Should show the previously saved option like Always expand groups or Expand recent activities
I confirm there is a bug :)
Git commit fad7b0e95cbaf038125c827bae9af42f29273926 by Montel Laurent.
Committed on 02/01/2013 at 23:19.
Pushed by mlaurent into branch 'KDE/4.10'.
Fix Bug 312500 - kmail can't set always expand groups
M +16 -9 messagelist/utils/aggregationeditor.cpp