When I logout/login or reboot, kmail does not restore itself. When I exit my kde session, I usually leave kmail running in the system tray. In the past, it used to restore both the system tray icon and the main window (that was a bug actually, it should restore only the system tray icon and hide the main window, as it was before logout). Now I notice that it doesn't restore any of them. However, kmail still opens and runs in the background and it asks me for my password when it is about time to fetch the mails, etc...

Steps to reproduce:
1) Open kmail, configure it to have a systray icon.
2) Close the main window and leave kmail running in the system tray.
3) logout and login
4) After kde has started, kmail is running but there is no systray icon or main window.
Bonus: if it is configured to fetch emails every x minutes and you don't have the password saved or the password is saved in a locked wallet, wait for x minutes and watch it asking for your account or wallet password...