Background: Using Openbox + gnome-panel on Ubuntu 12.04.2 (x86_64), kernel 3.5, with 4 GB RAM.

Problem: Mousing over or keyboard+arrow -ing through any LibreOffice entries in the Office submenu of gnome-panel shows a noticeable delay.

This delay is noticeable, anywhere from .2s to 2s (anecdotal estimation) and does not exist for any non-Libreoffice entry in gnome-panel.  This is _not_ a first-time-only caching issue: when I hit up-and-down repeatedly enough times and then stop, I can watch two different menu entries get iteratively selected over an additional 5s as it "catches up" with my keystrokes.

NB: LibreOffice is _not_ open.  I'm assuming there's some interaction with .desktop files.

Per conversation with vmiklos on IRC, I installed the latest master build.  Copied from about box:

    Version: 4.2.0.0.alpha0+
    Build ID: b1c4046379b888bf3a82fbd31287ee3a68439968
    TinderBox: Linux-x86-64@8-SLED11, Branch:master, Time: 2013-07-09_00:35:08

I first recall seeing this in 3.6, so have listed that as the affected version, but it still exists per the alpha build listed above.

Nothing jumps out at me from a cursory inspection of gnumeric.desktop and writer.desktop, other than perhaps 2 Exec lines in writer.desktop, or the fact that it's symlinked.