show the backgroundpixmap of QMenuBar??-Qt-3.3.6

[bigbigmoon]

hello,everyone!
I have a problem between Qt-3.3.5 and Qt-3.3.6 .
the codes like these:

QPixmap app_Normal;
app_Normal.convertFromImage(app_normal);
menuwgt=new QFrame(this) ;
menu1=new DMenuBar(menuwgt) ;
menu1->setPaletteBackgroundPixmap(app_Normal);

QPixmap app_Normal;
app_Normal.convertFromImage(app_normal);
menuwgt=new QFrame(this) ;
menu1=new DMenuBar(menuwgt) ;
menu1->setPaletteBackgroundPixmap(app_Normal);

To copy to clipboard, switch view to plain text mode 

it runs well when it's under FC5 ,but doesn't show the backgroundPixmap when in FC6,
I don't know what's the problem with it??????

it uses QT-3.3.5 in FC5 but QT-3.3.6 in FC6.

Thanks