The test file of the bug 689918 renders with a brown rectangle at top of page, which doesn't appear with Adobe.
Well I'm not sure whether the problem is with a shading, but that's very likely. It is visible with no banding on ppmraw with default resolution : ..\..\gs-hd\bin\gswin32c.exe -IF:/AFPL/gs-hd/lib;f:\afpl\fonts -dNOPAUSE - dBATCH -sDEVICE=ppmraw -sOutputFile=cur.ppm decompr-L01-001-K-12345600- 00DSG60k-.pdf I could minimize the document with removing almost all except the Windows logo. 3 characters 'i' near the logo can't remove with Acrobat 8. But it is still too big for analyzis. The reduced file appears 3 times longer (36Mb) than the original one. Can't attach the reduced file now due to slow GPRS connection. Will do ASAP.
A simplified test file is copied to casper:/home/support/689982/Bug689982.pdf.zip
Patch to HEAD : http://ghostscript.com/pipermail/gs-cvs/2008-July/008464.html
The problem was also visible with no banding and with -dNOTRANSPARENCY.