Comment 41 for bug 872207

Currently, on my machine it's very deterministic, every time I use CTRL+ALT+Cursor keys to switch workspaces, Firefox menus start to disappear (I can re-enable them by minimizing and maximizing). And it's not just menus, all drop-down lists, including awesome bar functionality (I cannot search history, because there isn't history drop-down list), also don't work. If I use ALT-TAB to switch between applications on different workspaces, menus don't disappear (I'm not sure for this; I'll try to use ALT-TAB exclusively to see if this is true). The problem is that I often use CTRL+ALT+Cursor keys (and the answer that I just don't use them I don't consider as an answer).