The problem I have is I print 25 copies of the bid list for the Monday sales meeting. On XP, I would see it count through the number of pages in the report (usually 8-10 pages) then it would send that to the printer and I would get 25 sets of 4-5 pages (double sided). On Windows 7, when I do the same thing I see it count through the 8-10 pages 25 separate times, then it would staple them all together as one. Using specific drivers- level 3 postscript from Xerox.com
The driver on both OS's is the same. So either try another driver from Xerox.com (Global/PS/PCL) or it will be at the Application level, some versions of Adobe reader and Acrobat will do that. It is called Host Collation, it sends the job as one big file instead of digitally telling the printer to do 25 copies.
Adobe has a link and workaround for it, but I would suggest the driver change.
http://helpx.adobe.com/acrobat/kb/pdf-files-printed-acrobat-do.html