MS applications produce inconsistent postscript

I am connecting to a Common Unix Printer System (CUPS) with mixed
results. Some applications produce postscript that works correctly
(e.g. PowerPoint, Notepad and Lotus Notes) while others (Word, Excel,
IE) produce postscript that scales the output 4x. When I look at the
postscript files, I see that the successful applications produce a
consistent file from the beginning through the prolog (e.g., comment,
prolog). The failing applications do not produce the same prolog as the
successful applications. I'm using an Apple Color LW 12/660 PS driver
is all cases and have ensured that all print attempts have scaling set
to 100%. The differences in the prologs seems to indicate Windows XP
has different postscript rendering engines which would account for the
different results. Does anyone have good understanding of XP's handling
of postscript printers? or why the applications are producing varying
results?