Version:           unspecified (using KDE 4.8.0) 
OS:                Linux

Window Menubar widget loads in plasma panel, but no menus are visible or clickable in the panel, for any application. This has been the case following a significant set of updates to plasma workspace software on 2012-02-03. Here's the full list of updates from /var/log/apt/history:

Start-Date: 2012-02-03 16:54:35
Install: gnome-shell-common:i386 (3.2.2.1-0ubuntu0.1)
Upgrade: chromium-browser-l10n:i386 (16.0.912.75~r116452-0ubuntu0.11.10.1, 16.0.912.77~r118311-0ubuntu0.11.10.1), plasma-dataengines-workspace:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), plasma-netbook:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), chromium-codecs-ffmpeg:i386 (16.0.912.75~r116452-0ubuntu0.11.10.1, 16.0.912.77~r118311-0ubuntu0.11.10.1), libsolidcontrol4abi2:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), gnome-shell:i386 (3.2.1-0ubuntu1.1, 3.2.2.1-0ubuntu0.1), libkscreensaver5:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), usbmuxd:i386 (1.0.7-1, 1.0.7-1ubuntu0.11.10.1), brasero-cdrkit:i386 (3.2.0-0ubuntu1, 3.2.0-0ubuntu1.1), linux-headers-3.0.0-16-generic-pae:i386 (3.0.0-16.27, 3.0.0-16.28), freespacenotifier:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), python-software-properties:i386 (0.81.13.2, 0.81.13.3), brasero-common:i386 (3.2.0-0ubuntu1, 3.2.0-0ubuntu1.1), gir1.2-accountsservice-1.0:i386 (
0.6.14-1git1ubuntu1, 0.6.14-1git1ubuntu1.1), plasma-widgets-workspace:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), libdecoration0:i386 (0.9.6+bzr20110929-0ubuntu6, 0.9.6+bzr20110929-0ubuntu6.1), kde-workspace:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), libkephal4abi1:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), linux-headers-3.0.0-16:i386 (3.0.0-16.27, 3.0.0-16.28), lightdm:i386 (1.0.6-0ubuntu1.2, 1.0.6-0ubuntu1.3), kde-workspace-kgreet-plugins:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), chromium-browser:i386 (16.0.912.75~r116452-0ubuntu0.11.10.1, 16.0.912.77~r118311-0ubuntu0.11.10.1), accountsservice:i386 (0.6.14-1git1ubuntu1, 0.6.14-1git1ubuntu1.1), klipper:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), linux-image-3.0.0-16-generic-pae:i386 (3.0.0-16.27, 3.0.0-16.28), ksysguard:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), libplasma-geolocation-interface4:i386 (4.8.0b-11.
10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), linux-libc-dev:i386 (3.0.0-16.27, 3.0.0-16.28), kmenuedit:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), libprocessui4a:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), compiz-plugins-default:i386 (0.9.6+bzr20110929-0ubuntu6, 0.9.6+bzr20110929-0ubuntu6.1), compiz-plugins:i386 (0.9.6+bzr20110929-0ubuntu6, 0.9.6+bzr20110929-0ubuntu6.1), libksgrd4:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), libaccountsservice0:i386 (0.6.14-1git1ubuntu1, 0.6.14-1git1ubuntu1.1), kde-window-manager-common:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), libkdecorations4:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), liblightdm-gobject-1-0:i386 (1.0.6-0ubuntu1.2, 1.0.6-0ubuntu1.3), libkwinglutils1:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), kdebase-workspace-dev:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), kded-appmenu:i386 (0.1-0ubuntu0.1~gnumdk1,
0.1-0ubuntu0.1~gnumdk2), libplasmagenericshell4:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), systemsettings:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), libkwinglesutils1:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), kdm:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), libkworkspace4abi1:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), vino:i386 (3.2.0-0ubuntu1, 3.2.0-0ubuntu1.1), kde-style-oxygen:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), software-properties-common:i386 (0.81.13.2, 0.81.13.3), kinfocenter:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), software-properties-gtk:i386 (0.81.13.2, 0.81.13.3), libbrasero-media3-1:i386 (3.2.0-0ubuntu1, 3.2.0-0ubuntu1.1), software-properties-kde:i386 (0.81.13.2, 0.81.13.3), ksysguardd:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), libusbmuxd1:i386 (1.0.7-1, 1.0.7-1ubuntu0.11.10.1), libweather-ion6:i386 (4.8.0b-
11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), plasma-desktop:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), libplasmaclock4abi3:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), libksignalplotter4:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), brasero:i386 (3.2.0-0ubuntu1, 3.2.0-0ubuntu1.1), compiz:i386 (0.9.6+bzr20110929-0ubuntu6, 0.9.6+bzr20110929-0ubuntu6.1), liblsofui4:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), libtaskmanager4abi3:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), compiz-core:i386 (0.9.6+bzr20110929-0ubuntu6, 0.9.6+bzr20110929-0ubuntu6.1), libprocesscore4abi1:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), plasma-scriptengine-python:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), libsolidcontrolifaces4abi2:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), kde-window-manager:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10),
kde-workspace-data:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), kde-workspace-bin:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), linux-firmware:i386 (1.60, 1.60.1), kde-workspace-dev:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10), compiz-gnome:i386 (0.9.6+bzr20110929-0ubuntu6, 0.9.6+bzr20110929-0ubuntu6.1), libkwineffects1abi3:i386 (4.8.0b-11.10ubuntu1~gnumdk5, 4.8.0b-11.10ubuntu1~gnumdk10)
End-Date: 2012-02-03 17:05:42

Reproducible: Always

Steps to Reproduce:
Download upgrades as listed in details above, then reboot. My desktop setup mimics Mac OS X. I have a default panel at the top, with a KDE Application Launcher in the top left corner, and a set of other widgets from the right. The widgets on the right do not obscure the Window Menubar widget. The Window Menubar widget occupies two-thirds of the panel, providing plenty of space for menus.

Actual Results:  
All Plasma components load and function as expected. Window Menubar widget loads, but no menus are visible in any application; Window Menubar can be moved or removed from the panel as normal.

Expected Results:  
Menus in the widget should load as the panel loads, with at least one menu item labeled "Menu" with an empty desktop. Application menus should load in the panel when an application is loaded. The menus should be that of the frontmost application.

Before the updates of 02-03-2012, I used both Oxygen and QtCurve widget themes, both with no problems. In QtCurve, I had the menu shortcut keys turned off, also with no problems.

My updates do include the KDE Backports PPA.

I'm hoping to avoid having to go back and uninstall each of the packages until I get the menus back. But if the maintainers cannot fix the problem on their end, I'll be open to doing that.