[arch-general] QtCreator help font problem

I noticed in the help section of qtcreator ( version 2.5 installed from repo), the font size is small for me , as usual I tried key combination like(ctrl + +,ctrl+mouse wheel), but doesn't work properly, only the titles get zoomed in. And I changed setting in the options->help->font , also only titles zoomed in. The first page of help section of qtcreator can be zoomed in/out properly. But in many other pages (like QStyle page) only the title can be zoomed in/out. The qtcreator (2.4.1) installed from the official website qtsdk*.run installer doesn't have this problem. Anyone experiencing the same? Should I open a bug report?