I did. It only works if the report type is "Portrait" AND Paper Size is "Custom". I wonder then the interest of a wizard step being dedicated to choose the paper size if we SHALL not use it...Please, try to set the same Orientation

After replacing StimulSoft 2011.2 Ultimate by the 2013.1 version, my application seems to run stable. No printing error anymore. What is not so reassuring to me with the use of StimulSoft's is that I'm/you are still not able to point a cause, which is not that intellectually satisfying in a Crystal Reports/StimulSoft challenge point of view.
Thanks guys anyway for the help you provided, I do appreciate.
Jean-Yves
Edit: I don't know how to tag the topic as solved, so I changed the subject label. Please do fix this.