Okay that Menu App appears to be the main Gnome Menu which definitely indicates its an issue outside of GnoMenu itself and may be related to the following Bug #12040 ( vhttps://bugs.launchpad.net/ubuntu/+source/gnome-panel/+bug/12040 )for Gnome Main Menu. Not absolutely sure but if we turn off menu caching in Gnome it may solve your issue.
Okay that Menu App appears to be the main Gnome Menu which definitely indicates its an issue outside of GnoMenu itself and may be related to the following Bug #12040 ( vhttps: //bugs. launchpad. net/ubuntu/ +source/ gnome-panel/ +bug/12040 )for Gnome Main Menu. Not absolutely sure but if we turn off menu caching in Gnome it may solve your issue.