Update manager won't open when clicked

Status changed to 'Confirmed' because the bug affects multiple users.

I've had this problem for a few releases now. It seems that the Update Manager window is "open" somewhere, but clicking on the launcher icon does not take me to it or change workspaces. My workaround is to right-click the launcher icon, select "Quit" from the menu (upon which the number of packages to install disappears from the icon), and then click on the icon once more, which always causes the application to launch successfully.

This may be nothing, but I have a suspicion that it might be related to a feature I've selected in the CompizConfig Settings Manager. Under General Settings -> Focus & Raise Behaviour, I have "Click to Focus", "Raise on Click" and "Auto-raise" all unselected. I've had similar problems in other applications (e.g., Thunderbird) with windows not being raised when the should be, possibly as a result of these settings.

I'm seeing this problem too, but the three options Todd mentioned are all selected in my Compiz Config Settings Manager, so I guess the problem isn't there.

I am also seeing this exact problem.

Also have this problem. Only happens when the update manager launches itself. Strangely it seems that if I catch it right away, the window appears, but if it sits un-noticed and minimized in the launcher (for some unmeasured period of time) then I have to right-click quit and manually relaunch it to get it back.

Duplicate of https://bugs.launchpad.net/unity/+bug/1003950 ?

I am also experiencing this exact same issue. The only tid-bits I can add is that this problem is seen on both of my dual-monitor systems, but seems to work fine on my single monitor system. All 3 are nvidia cards with the accelerated driver.

Seeing the exact same issue here with a dual-monitor nvidia system. Todd's suggestions don't help in my own case as it appears the window is not actually open in any workspace--the only way to review pending changes seems to be to explicitly quit Update Manager and relaunch it manually.

Affects me as I type this. In Unity the Updates Available Icon in the left taskbar shows 6 updates available. Checking the upper taskbar on the right under the On/Off icon, the menu shows Updates Available. However, left-clicking either of these produces no results. Right-clicking the left-hand Updates Available icon displays the choices 'Check for Updates', 'Install All Avalable Updates', and 'Update Manager' (which I must assume from the context that it should open the Update Manager Window); selecting 'Install All Available Updates' works, but I am in the habit of reading which updates are pending before installation. This is not possible with the GUI using the displayed icon at this time. This is Ubuntu 12.04 with all updates except the 6 updates shown as pending.

I still have this problem. This issue is marked as resolved: https://bugs.launchpad.net/unity/+bug/1003950 , but in fact it does not.

This is because of atk (accessibility toolkit).
gconftool-2 --set "/desktop/gnome/interface/accessibility" --type bool true

I experience that very often.
I do "right click" -> "quit" then open the update manager again (the it works ok).
But it's a bug.

I have ubuntu 12.04.
I had this problem and found I had changed my startup applications menu a few days before. To fix click on the start button in top right corner then select to startup applications and restart your computer after changing..
make sure the follow boxes are checked:
Certificate and key storage
Gnome settings daemon
policykit authentication agent
SSH key agent
This allowed me to install my updates, open package manager and install software from software center.
When I unchecked these 4 boxes I lost the root rights. After checking the boxes and retarting they all worked fine.
Hope this helps.
RR