This week I’ve received four times the same (i.e. duplicated) ViewSourceWith (VSW) bug report that sounds…
“ViewSourceWith stopped to show the icons on context menu, this regression is present on Karmic Koala (Ubuntu 9.10)”
I use Intrepid Ibex (Ubuntu 8.10) and all works fine, so I’ve burned a Karmic Koala ISO and tested it discovering the “regression” exists.
Debug -> Add logs -> Remove logs -> Clean Profile -> DOM Inspect -> MozRepl without find where the problem occurs.
Last resort -> Bugzilla -> Found!!!
The Bug 527253 unveils the mystery!
This isn’t a regression
ViewSourceWith isn’t the guilty, Firefox isn’t the guilty but… Gnome is the guilty 
Type the command shown below from command line and restart Firefox
gconftool-2 --type bool --set /desktop/gnome/interface/menus_have_icons true
EDIT Or use the UI to obtain same result (thanks to mzz) system -> preferences -> appearance -> interface -> show icons in menus
This worked for me and also for two bug submitters (the other two guys do not replayed to my hint)
So remember Bugzilla is your friend 
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