Q3TabDialog problem

[batileon]

After porting my program from QT3 to QT4, I found that the tabs are all disappeared!!!
The tabs can only be shown when there's no parent widget parsed to the Q3TabDialog.

I have a class inherited the Q3Dialog class with constructor like this

TESTTabDialog::TESTTabDialog( TESTListViewItem* lvi, QWidget *parent, const char *name, bool modal, Qt::WFlags f)
	:Q3TabDialog(parent, name, modal, f)
{
............
}

TESTTabDialog::TESTTabDialog( TESTListViewItem* lvi, QWidget *parent, const char *name, bool modal, Qt::WFlags f)
	:Q3TabDialog(parent, name, modal, f)
{
............
}

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When I parse a NULL to the "parent" parameter, the tabs can be shown, however the Tab Dialog is not at center place and cannot get active control.
When I parse the actual parent to the parent parameter, the tabs all disappeared and I cannot select other tab page, only the first tab page can be shown.

Can anyone tell me what's wrong with it and how can I solve it?
Thanks a lot!

[batileon]

i found that in qt4
tabdialog should be drawn manually by adding tabs to qtabwidget
is that true?