adding a QCheckBox to a QLayout makes QWidget not display -- no matter how its added

Hello,

I'm adding a QCheckBox to a QLayout. The QWidget in which the QLayout resides is not being displayed under Windows 7. It is shown in the taskbar and I can maximize it from there thus making it display but it is not displayed as a regular window. No matter what I tried to get the QCheckBox into the QLayout.
Here's the code:
Code:

private: QSize size; QBoxLayout* boxLayout; QFormLayout* formLayout; QLabel* label; QDoubleSpinBox* doubleSpinBox; QLabel* label_2; QDoubleSpinBox* doubleSpinBox_2; QLabel* label_3; QDoubleSpinBox* doubleSpinBox_3; QLabel* label_4; QDoubleSpinBox* doubleSpinBox_4; QLabel* label_5; QCheckBox* checkBox;
Declared inside X.h
Code:

X::X() : size(202,157) { boxLayout = new QBoxLayout(QBoxLayout::TopToBottom, this); formLayout = new QFormLayout(); label = new QLabel("a"); doubleSpinBox = new QDoubleSpinBox(this); doubleSpinBox->setDecimals(3); doubleSpinBox->setMaximum(1); doubleSpinBox->setSingleStep(0.001); formLayout->addRow(label, doubleSpinBox); label_2 = new QLabel("a"); doubleSpinBox_2 = new QDoubleSpinBox(); doubleSpinBox_2->setDecimals(3); doubleSpinBox_2->setMaximum(1); doubleSpinBox_2->setSingleStep(0.001); formLayout->addRow(label_2, doubleSpinBox_2); label_3 = new QLabel("a"); doubleSpinBox_3 = new QDoubleSpinBox(); doubleSpinBox_3->setDecimals(3); doubleSpinBox_3->setMaximum(1); doubleSpinBox_3->setSingleStep(0.001); formLayout->addRow(label_3, doubleSpinBox_3); label_4 = new QLabel("a"); doubleSpinBox_4 = new QDoubleSpinBox(); doubleSpinBox_4->setDecimals(3); doubleSpinBox_4->setMaximum(1); doubleSpinBox_4->setSingleStep(0.001); formLayout->addRow(label_4, doubleSpinBox_4); boxLayout->addLayout(formLayout); checkBox = new QCheckBox("a"); //boxLayout->addWidget(checkBox); // enabling this line makes the QWidget X not display }
I tried adding a label and the QCheckBox to the QFormLayout and didn't have the QBoxLayout but it didn't work. I thought it's perhaps the QFormLayout only accepting "input QWidgets" and QCheckBox isn't defined as an "input QWidget" according to QDesigner, thus I switched to a QBoxLayout containing a QFormLayout and a QCheckBox to no avail.

:confused: Help!

Lars