I think I found the problem area for Defaul Zoom. It's stored in the this key:
I looked at the hex values for all the possible zoom settings, listed here:
zoom = hex
25 = 4000
50 = 8000
75 = c000
100 = 0
125 = 14000
150 = 18000
200 = 20000
400 = 40000
800 = 80000
1600 = 100000
3200 = 200000
6400 = 400000
If the hex values marched out evenly, 100% should be 10000(H), not 0(H).
I manually entered 10000(H) in the Registry. In Adobe reader 9.3.0 and looked at the Default Zoom setting (Edit -> Preferences -> Page Display -> Zoom). The setting was 150%, which I had already seen as 18000(H) in the Registry when I went through all the possible zoom settings previously.
I realize a pdf document may be created with its own default zoom setting which my preferences won't override, but this is also happening with pdf documents I create myself with PDFill. This lack of zoom control with my own documents didn't happen with Adobe Reader 7.0.9.
I also noticed the key just below iDefaultZoomScale is iDefaultZoomType, which is currently set at 0(H). I haven't found its counterpart in Adobe Reader's preferences. Any idea what it does?
Fixed it. I downgraded to 8.3.2, where I could override a document's default page layout and zoom setting. Here's a perfect example a software publisher ruining a good thing with a newer software version. Sometimes BETTER is the enemy of GOOD.
I too have this problem. Adobe Reader 9 also has printing problems WYSI(not)WYG in the print preview. I have a HPScanJet6350 and when I scan at 200 dpi, I get fairly large actual sizes 16 x 20 inches in Adobe, but they are actually 8.5 x 11 pages I'm scanning. To the best of my knowledge this is what resolution is, OK anway......... but even trying to print as an image and/or fitting to width will not save the setting after I close. I changed the default layout, zoom, and resolutions (in preferences) but to no avail will anything save these defaults. "Restore Last View Settings" also will not help. Having these issues broken from previous versions is frustrating. Adobe is a huge headache because I print MANY PDFs from email by right clicking and selecting print rather than opening up Reader EVERYTIME and modifying print settings. I thought I could help Adobe become aware of this bug. An answer would be nice since I have bought several licenses of Acrobat over the years...
Believe it or not (if you use Adobe Reader you will believe it of course), but 7 years later this is STILL broken.
Not only does it ignore the preferred zoom setting, but if you set it to 100%, it doesn't even save it in the registry. It only saves it if you select a setting different from 100%, and even then it subsequently just ignores it when you open any document.
Version 9.3.0 is old and unsupported.