ugly fonts

I have downloaded and compiled qt 4.7.2 and my qt apps got this ugly alised fonts
what can I do to get rid of them ?

I'm running on ubuntu, did the xml thing mentioned in other forums (under ~/.fonts.conf), got qtconfig, called setStyleStrategy on application main font, and none of them worked.
I got qtconfig4 and the app itself seems like it is qt made, and the fonts on that app are ok, I thought that might be a problem with building Qt, but I didn't configure -no-fontconfig , and also the qtconfig seems to take effect on my app when changing font family and other stuff !

did I miss something in my code ? or building Qt ?

It is solved, in case of anyone else encounters the same thing, I have rebuilt the Qt using -fontconfig flag. it is mentioned in the document that it is the default flag, but it seems, that it wasn't !

It is the default flag but maybe your system was lacking required development files for fontconfig and configure skipped the flag as unusable. It should mention that fact in configure logs.