Greetings,
some time ago I tried to upgrade my QT version from 3.2.3 to 3.3.1.
I tried that both by using the slackware official package and by compiling from sources.

Sadly I had to downgrade because I have experienced nasty issues, in fact many of my fonts simply vanish when I upgrade.
Note, this has nothing to do (I guess) with the known problem with fonts in qt 3.3.1, I already applied the patch (qfontdatabase_x11.diff) which is available for that issue. But that didn't lead to solution at all.

Since a lot of fonts are missing (which is quite undesiderable), many programs look horrible.
In order to let people understand better the problem, I made some screenshots. I'm sorry I can't show them, because I can't place urls here until I write at least five posts (for spam prevention... in my humble opinion this only damages honest users, sadly a spammer could spam anyway if he wanted to).

So I'm writing down some of the fonts available in a KDE font selection dialog with QT 3.2.3 (I have all my fonts available with this version):

Arial
Arial Black
Arial Black [Monotype]
Arial [Monotype]
Bitstream Charter
Bitstream Charter [Bitstream]
Bitstream Vera Sans
Bitstream Vera Sans Mono
Bitstream Vera Sans Mono [Bitstream]
Bitstream Vera Sans [Bitstream]
Bitstream Vera Serif
Bitstream Vera Sans [Bitstream]
Charter
Clean
Clearlyu
Clearlyu Alternate Gliphsa
Clearlyu Arabic
Clearlyu Arabic Extra
Clearlyu Devanagari
Clearlyu Devangari Extra
Clearlyu Ligature
Clearlyu Pua
Comic Sans MS
Comic Sans MS [Microsoft]
Courier
etc.etc..........


This is instead the same font selection dialog with QT 3.3.1 (a lot of fonts have been wiped out):

Arial
Arial Black
Bitstream Charter
Bitstream Vera Sans
Bitstream Vera Sans Mono
Bitstream Vera Serif
Comic Sans MS
Courier
Courier 10 Pitch
Courier New
Cursor
Eklektic Normal
Estrangelo Edessa
Franklin Gothic Medium
etc.etc.........


It also wipes out one of the fonts I use a lot, "Fixed".

Recently QT 3.3.2 came out, I gave that a shot using the slackware package available in /testing , but it gave me the same exact problems.
I was thinking... my KDE is compiled with qt 3.2.3... maybe I have to compile it with qt 3.3.1 to let fonts work? Since this would require much time for me, right now I can't try this until I'm sure it fixes everything. Too bad.

I wonder if someone has fallen in this problem too, I would be really glad to know if there's a way to fix it (maybe some configuration files need to be corrected for QT 3.3.x ?).

Best regards to all LinuxQuestions community,
Giacomo