Some Fonts not antialiased anymore on Firefox and QT4

[Michele Costantino Soccio]

After a recent update of my Hardy box, some of the fonts are not antialiased any more on some applications like Skype (and all the qt4, checked using qtconfig-qt4) and also Firefox (it depends on website).
I did not change any font config neighter in my home directory (eg .fonts.conf) neighter in /etc/fonts. By the way, I also tried to create a new user, but also the newly created user still has to face this issue.
I'm not sure which package influences this (maybe fontconfig?).
I attach a couple of image to better explain.
I have backports and proposed repository activated.

[Dereck Wonnacott (dereck)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. Could you please attach the files in /var/log/dist-upgrade to this bug report?

This will greatly aid us in tracking down your problem.

[Michele Costantino Soccio (michelinux)]

I attached the files you asked. Please let me know whether there is anything more I could do.

(by the way: this problem started about one month after I dist-upgraded from gutsy to hardy)

[Michele Costantino Soccio (michelinux)]

Just tried to uninstall all the KDE4/QT4 applications I had except for
Skype (I really liked Okular) and it solved the problem.
Contact me if you wanna ask more info.
Thanks for support!

[Michele Costantino Soccio (michelinux)]

Just ignore my precedend message: it solved only on the Skype, but the issue still affects Firefox.

[onyxrev (entp)]

Jaunty 9.04 Alpha daily build as of March 19

This, or something like it, is happening to me on any site that defines Helvetica as the default font in its css. I happen to have the full Helvetica line installed as my employer uses it extensively. Most users would probably fall back to Arial or freesans, which displays correctly.

My fonts are set to the LCD setting (slight hinting and subpixel smoothing at 96dpi).

See screenshot.

[onyxrev (entp)]

Oh, and I do have KDE4 apps installed if that is indeed related. Doesn't matter if I'm in KDE or Gnome, though.

[Miguel Sanjurjo (charruah)]

I use Gentoo and had the same problem, now I have solved it.
The issue was that in most systems Helvetica falls back to Arial, which has no problem at all.
Now, I had a bitmap font called Helvetica (under 75dpi, we all have it I believe...), and because fc-cache was also registering bitmap fonts, this ugly thing was being used by Firefox in all pages that have Helvetica as default font in their CSS. (for example the page I used for testing: http://www.ubuntu.com/getubuntu/upgrading).
Solution: Take 70-no-bitmaps.conf into action. In Gentoo it's activated via te eselect interface, I don't know how it is done in other distros, but I'm sure the file is there. With this rule fc-cache ignores these kind of fonts, leaving the system without a font with the name Helvetica, and so forcing the browser to fall back to something equivalent.
Another solution would be to write another rule which states that for every Helvetica-call the Arial font should be used, but this is more complicated in my opinion

[Vish (vish)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. You reported this bug a while ago and there hasn't been any activity in it recently. We were wondering if this is still an issue for you. Can you try with the latest Ubuntu release? Thanks in advance.

[Launchpad Janitor (janitor)]

[Expired for fontconfig (Ubuntu) because there has been no activity for 60 days.]