User-Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.0; Trident/4.0; SLCC1; .NET CLR 2.0.50727; Media Center PC 5.0; .NET CLR 1.1.4322; .NET CLR 3.5.21022; .NET CLR 3.5.30729; .NET CLR 3.0.30729) Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.1pre) Gecko/20090613 Lightning/1.0pre Shredder/3.0b3pre The preview pane is always enabled now. I open up Thunderbird and it is enabled. I hit F8 and it goes away. Once I open up Thunderbird again, or go to a different folder view, the preview pane is enabled again. Reproducible: Always Steps to Reproduce: 1. Open up Thunderbird. 2. Hit F8 to close out of Preview Pane. 3. Either open up a different folder or close and reopen Thunderbird, the preview pane is enabled again. Actual Results: The preview pane does not stay disenabled. Expected Results: The preview pane should stay disenabled if that is the preference of the user.