Fix the problem where the thread pane / message pane splitter would always move and

"creep" up when you displayed messages. thanks to evaughan for helping me figure this out.

mailnews/base/resources/skin/messenger.css

@@ -323,5 +323,7 @@ menu.push[disabled="true"]:active {
 box#messagepanebox
 {
    min-height: 10px;
+   height: 0px;
 }
 
+