I also have seen some font problems in the Linux version of Nokia Qt SDK simulator. This might be related to problem which SaiPrasad2010 mentioned earlier in this thread.
Eg if your application shows a splash screen before the main window then texts in your main window show up wery small. The problem shows only when you are running application using simulator, not when you are running app on device. So I think it is a bug in the simulator. Try to run following application on Linux using current Nokia Qt SDK simulator: Make sure that simulator starts in the one of these view modes: Symbian Touch, Symbian non Touch or Symbian ^3. The problem does not show if simulator starts in the Maemo Fremantle mode. Also if you manually switch view modes then problem disappears
The text of QLabel shows wery small. It happens atleast on Linux, I don't know about Windows. If you comment out lines related to splash screen then problem disappears.
int main(int argc, char *argv)
QApplication a(argc, argv);
QLabel w("Hello World!!");
It really does not matter if your main widget is QLabel, sub class of QMainWindow or something else. It also does not matter if you use show(), showMaximized() or showFullScreen(). It also does not matter if you set a pixmap for the splashscreen or not. Text in the main widget show up always wery small. The problem goes away if you don't show the splash screen at all.
As I said there is no problem when running application on device. I'm using Debian 5.0 'Lenny', but I don't think it should matter what linux distro you are using.