Disabling autoscale is not wirking

[P@u1]

Hi Everyone,

in my program I want to be able to disable the autoscale for the y-axis and reenable it later.
I use a checkbox for this:

//std::vector<QwtPlot*> plots_;
void MainWindow::on_freezeScaleBox_toggled(bool on)
{
	for(int i = 0; i < plots_.size(); ++i)
	{
		plots_[i]->setAxisAutoScale(QwtPlot::yLeft, on);
	}
}

//std::vector<QwtPlot*> plots_;
void MainWindow::on_freezeScaleBox_toggled(bool on)
{
	for(int i = 0; i < plots_.size(); ++i)
	{
		plots_[i]->setAxisAutoScale(QwtPlot::yLeft, on);
	}
}

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When I first disable the autoaxisscale and then add some curves and some data, it is autoscaled anyway...
Any suggestions?