Problem with drawing pdf in RooPlot

I have a trouble plotting with RooPlot when there are plotting from histpdf of unequal binning. I do a 3D fit using RooFit in which one of the variable is of two bins which are not equidistant. The fit converges and give me result what exactly i expect. But when i plot all three of them using RooPlot the variable which unequal binning the total number of events on the plot are less then expected. I have attached the plot.
RooPlot* xframe4 = lep.frame(“lep”) ;
d_data2->plotOn(xframe4) ;
I expect about 40k events and the first two plots are correct but the third plot is 33K events.
So i looked and found an option.
and tried to plot using
d_data2->plotOn(xframe4 ,DataError(RooAbsData::SumW2));
which give the the data point correct but pdf is wrong.Attaching the plot as well.
Can any one please help me on this one.
fit_svd1_lepgen1.pdf (22.2 KB)
fit_svd1_lepgen1.pdf (22 KB)

May be a small script reproducing the problem will help to understand it …