Adding Arabic fonts and CJK (China Japan Korean) fonts

Our Embedded Application already consists of CJK (China japan korean BDF format) fonts.
I am trying to add Arabic font to the application .
If any one of the font is loaded (CJK or Arabic) its working, but when both font files (BDF format) are added its not displaying any thing related to Arabic fonts.

BDF fonts are added to Application using QFontDatabase::addApplicationFont.
I am using QT 4.7.3 on linux.
This function is also not returning -1, which indicates fonts are loaded successfully.

Any suggestion ?

Thanks in Advance,

Kishore