There appears to be a problem with the Toad Data Modeler (v5.0.5.31) and landscape printing. When I try to send a model to the printer, I get the following error "The Margins are set outside of the printable are of the page. Do you want to continue". It may be possible that Toad Data Modeler is not sending the correct dimensions to the printer when landscape orientation is chosen, but I don't have a way to prove that.
Our printer is a brand new HP DesignJet T120, and is loaded with 24" roll stock. If I have Toad Data Modeler page setup as Portrait, it prints fine, but if you change it to Landscape it will not print.
Also, I tried printing the report ERD_0.png in landscape mode from another utility, and it printed, but the quality of the PNG file is insufficient for printing. Is it possible to generate a higher quality image? I realize the size would increase, but the image isn't that big to begin with.
Have you tried selecting Fit To Page on Page Setup? You might have some objects that are slightly outside of the margins for that orientation and that might get it to print. Also you can try reducing the margin sizes as well.
I am sorry for the print issues you are experiencing. We have had problems reproducing and testing these printing issues and we are planning on replacing the old print component to avoid them.
Nevertheless, there is an easy work around of the printing issues. Just use printing to some PDF printer (There are many free PDF printers, e.g. PDFCreator, PDF reDirect and many others) and then print to the printer.