Version: 1.9.1 (using KDE KDE 3.5.2) Installed from: Fedora RPMs OS: Linux This is very similar to bug 121866 but it's not identical. I've had this problem with kmail for a long time, don't know for how many versions though... While browsing my inbox a recurring problem is that instead of popping up the mail I click on there's a slight delay and then the message disappears from the list and the message next to it is displayed instead. This happens using IMAP (not sure of the make, Merak I think). The mail is not gone but the only way to get it to reappear in the list is to select another folder and then reselect the inbox. Refresh does not make them reappear. I think there was also a bug about the entire list vanishing when clicking on a mail on an IMAP account, this does seem related, I have seen this also, but not with my current installation.
I see similar symptoms (mails disappear from the list, sometimes reappearing after pressing F5, sometimes you have to go to another folder and back), but only after deleting one or more messages and only in Inbox, not in any other folders. The IMAP server is Dovecot 1.0 (beta). With another server running Dovecot 0.99 the problems don't occur, but looking at captured packages I can't see any significant difference between when deleting a mail from Inbox and deleting a file from elsewhere.
Please report if this is still an issue in recent kmail versions