Version:            (using KDE 3.5.9)
Installed from:    Slackware Packages
OS:                Linux

The following occurs when using IMAP.

Say there are 4 messages, m1 through m4;  KMail is displaying the messages sorted by order of arrival, where m1 arrived first and m4 arrived last.  Thus, the messages are ordered as follows:

m1
m2
m3
m4

To reproduce the bug, first select m3.  Message m3 is highlighted (denoted by "<-" below) and displayed:

m1
m2
m3 <-
m4

Now delete m3.  KMail highlights and displays m4.

m1
m2
m4 <-

Now press the left arrow key to select m2 (or click on m2).  KMail incorrectly updates the display, removing m2 from the list of selectable messages and leaving m4 selected and displayed.

m1
m4 <-

Pressing the left arrow again to move to the previous message results in the following:

m1 <-
m4

Essentially, m2 was skipped and has now completely disappeared from the selectable messages.  Using a web interface to the same email account, I am able to verify that m1 and m4 exist and are marked as read, m3 is marked as deleted, and m2 is marked as unread (assuming it was an unread message to begin with).  The list of messages in KMail remains incorrect until a rescan of the directory is done.

This bug makes it essentially impossible to read and delete messages with KMail.