Roofit plotOn for RooAbsData empty bins

dear experts, I write again my question here, since the roottak hypernews seems to be a low trafic list)

I fail to plot a RooAbsData without the empty bins. I mean i do have a data distribution with some empty bins, but when i plot the distribution, the empty bins are plotted with a marker as well.
How can i remove this feature?
I looked on the ROOT forum and found one suggestion which relies on the RooPlot::SetMinimum() solution, but this approach is not optimal especially in the case of plots with logscale set.
Is there some more formal prescrition one could apply here in order to NOT have the empty bins filled as well?
I don’t know if i am clear enough, but i would like that the empty bins are not filled with the marker.
thanks in advance.

RooWorkspace* w = (RooWorkspace*) file->Get(“combined”);
RooAbsData* data = w->data(“obsData”);

RooPlot* frame = obs->frame();
data->plotOn(frame,MarkerSize(2),Cut(Form("%s==%s::%s",channelCat->GetName(),channelCat->GetName(),tt->GetName())),DataError(RooAbsData::Poisson))
// how can i remove empty bins from the plot?

dear experts,
is there a chance to have some advise on how i could tackle this feature. I could of course simply retrieve the original histogram and plot it instead of the RooAbsData.
thanks.