Hmmm... I see "Enable systray Quickstarter" on the version of LibO on my
Ubuntu 11.04 setup, which I'm fairly sure is the one supplied with
Ubuntu (Help > About says "LibreOffice 3.3.2, OOO330m19 (Build:202) tag
libreoffice-3.3.2.2, Ubuntu package 1:3.3.2-1ubuntu5"). So I can supply
that picture if necessary.
I don't know why it's not showing on your LibO 3.4 setup. This is a good
example of the occasional differences between the LibO supplied with
Ubuntu (and possibly other Linux distros) and the LibO installed from
the LibO website. Also, at various times that selection was not
available in the Linux version of OOo, so it's possible that it's not
there even in the original LibO version.
Hmmm... another thought: on the General page, is "Enable experimental
(unstable) features" selected? I don't know if that makes any difference
in this case, but I've found that a lot of things that appear to be
missing suddenly show up when I select that option.
We've handled these o/s differences in the past by using a screenshot
from Windows and noting in the text that it's not found on all operating
systems, or may be worded differently. An alternative would be to use a
Linux screenshot (which I can provide) but include that item in the text
with something like "not found on all operating systems; called 'Load
LibreOffice during system start-up' on Windows". There are other options
that are Windows-only, or Linux-only, or Mac-only; I believe we handled
them in similar ways.
--Jean