The problem is that Thunderbird loses the selection when the view is updated. Views can be updated in a variety of ways, but the selected message should remain selected after the view change, or an appropriate message should be selected. To reproduce: - Use an IMAP account set to mark messages as deleted (not to move to a Trash mailbox) - Set the View to View->Messages->Not Deleted - Delete a few messages in an IMAP mailbox - Note that the deleted messages remain in view (could be considered a bug but let's ignore that for now) - Note which message is selected - Select View->Messages->Not Deleted - Note that the message you had selected is no longer selected as NO message is selected. Thunderbird should be smart about which message is selected after updating the view. In the example above, the message selected before selecting 'View->Messages->Not Deleted' should remain selected. If the view were set to View->Messages->Unread and you had a read message selected when you selected View->Messages->Unread again (to cause a refresh) the NEXT Unread message in the list should be selected, but Thunderbird should not lose the selection and end up selecting nothing as it is doing now.
This same problem happens when you use the new Archive feature. When you have a message selected and click the 'Archive' button (or press the 'A' key) the message is moved to the archives and your selection goes away. The 'next' message should get selected in this case, much like what happens when you delete a message.
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