If I switch from an (upright) text font to italic or oblique fonts, the pdfwriter gets confused and doesn't recognize landscape mode. I'll attach two Postscript files that are essentially identical except one uses normal Roman and the other uses italic as the default. When ps2pdf is applied to these, the outputs have different orientations (as observed in xpdf, acroread, kpdf, ... ).
Created attachment 3577 [details] uses normal Roman as default
Created attachment 3578 [details] uses "italic" (oblique) as default
I built 8.61 and its pdfwrite recognizes landscape when italic fonts are the default, but the document produced is upside-down!
ghostscript has some logic for 'guessing' the correct orientation by looking at the predominant text direction, but it may occasionally get it wrong with strange fonts (e.g. one which declares itself to be a symbol font, I think). I haven't tried with your files so I cannot confirm your report; but the actual page orientation can be specified manually when the auto-rotation does not do what you want - see the documentation of ps2pdf in the ghostscript doc directory.
> the actual page orientation can be specified manually when the auto-rotation does not do what you want But not if ps2pdf is called in a script and the pdf viewer doesn't have rotation commands on the grounds that it's the pdf-generator's responsibility to get the orientation right (e.g., kpdf). I've written a script that looks for "Orientation: Landscape" and does the right thing *before* ps2pdf. Why can't ps2pdf do the right thing? The assumption seems to be that Distiller must at all costs be emulated, even if it's an obvious bug. I'm not using a "strange" font or a symbol font; just an italic font.
Fixed in revision 9582, patch here: http://ghostscript.com/pipermail/gs-cvs/2009-March/009156.html
The patch works for me. Thanks.