Version: 1.11.0 (using 4.2.00 (KDE 4.2.0) "release 93", KDE:KDE4:Factory:Desktop / openSUSE_11.0) Compiler: gcc OS: Linux (i686) release 2.6.25.18-0.2-vk5ztv By default I had only Folder and Unread columns displayed in the folder list and Subject, Sender, Receiver and Date columns in Message List. After right clicking on the column headers in the folder list and selecting "Size", I discovered that all columns were now selected for display in the message list (some at zero width). After resetting to display only the columns I wanted, I then checked "Total" in the folder list. Again all columns were selected in the message list. Selecting "Show Default Columns" and "Adjust Column Sizes" in the message list appears to have stopped it recurring, at least for the time being...
can not reproduce with KDE 4.3. If you still can, please reopen and tell us which aggregation mode and theme you use in the message list.