The folder pane on the left has disappeared and I can't get it back. I've seen the early posts on this and reply ("If you don't see a folder pane it is probably because you inadvertently closed (collapsed) it (Bug 340982). To bring it back, just move your cursor to the far left side of the window until the cursor changes into a double-headed arrow (↔), and then drag the splitter bar to the right.") but this isn't working for me - when I get the double-headed arrow, this moves the edge of the Thunderbird window back and forth, it doesn't bring back the folder pane. Please help! Thank you.