User Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_6_8; en-us) AppleWebKit/533.21.1 (KHTML, like Gecko) Version/5.0.5 Safari/533.21.1 Steps to reproduce: - In Thunderbird I have one pane open with "All Folders" on the left hand side. - I right-click on a folder and select "open in new tab". - I go back to the original tab and collapse the hierarchy. - I click on the new tab again. Actual results: The folder hierarchy display in the other tab has changed. Even worse, if it is a multi-level hierarchy that has been completely collapsed, it is shown opened to an intermediate level. Expected results: The folders view of two different tabs should be independent of each other. A change in one view should not affect the view in the other tab.