QwtPlot - Revert to initial state after zooming has been cancelled

Hi,
I have a QwtPlot and would like to add panning and zooming capability. At the beginning the plot canvas as well as the scale axes are automatically and properly re-scaled after replot() when attaching or detaching QwtPlotCurves. (This has to be done as the data series to be displayed are selectable according some filters.) When I add a QwtPlotZoomer, then zooming works fine. But after cancelling zoom mode by right mouse button (default) the re-scaling does never work again. What means that the plot does not really revert to its initial state.
What can I do?

Thank's
Stefan

When you assign a scale explicitely (f.e. zooming in/out) autoscaling is turned off as long as you don't reenable it.

Uwe