firefox global browser.cache.disk.capacity set ignored

[Marco Menardi]

Kubuntu 12.04, firefox 11. I know that to set global preferences I have to act in /etc/xul-ext/ubufox.js.
Since I use squid, I want to disable FF own caching on disk, and since is a LTSP installation, I want to do it globally.
To disable from Option FF interface, I would have to disable smart cache and set it's value to 0.
But if I put these lines in ubufox.js:
Better would be mimic what could be done from Options interface, i.e.:
pref("browser.cache.disk.smart_size.enabled", false);
pref("browser.cache.disk.capacity", 0);
only the first parameter is taken, while the second is ignored and capacity is left to it's default value, so disk caching is not disabled.
As temporary workaround I've set pref("browser.cache.disk.enabled", false); it works, but is a bad solution since from FF Options interface is not possible to understand that is acting.
I expect instead that both parameters are take into consideration from /etc/xul-ext/ubufox.js.
Of course I tested removing the FF user's profile each time so I had a clean situation.

[Logan Rosen (logan)]

Is this the same issue as the one described at https://bugzilla.mozilla.org/show_bug.cgi?id=225863?

[Launchpad Janitor (janitor)]

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