This is intresting,
I have a similar Problem with my Ricoh's and Quark.
I have Ricoh Pro 1106ex and a 1135 I get flipped pages in Quark 7.5 as well.
I have seen it only happens In a situation of a New Master page. or a graphic page.
When a new Part or Chapter opener page happens the Page flips.
Indesign doesn't do this to my Ricoh's
Also when i create a PDF of the Quark page it seems to happen as well.
I wonder if Quark is throwing some information into the Postscript and PDF to do this