PDDocSaveWithParams does not change PDF version from 1.8 (Acrobat 9, Acrobat X) to 1.4

Question

Dear all,
this post seems similar to this discussion:
http://forums.adobe.com/message/1160826#1160826
but it is not.
Our customers prepare documents to be presented at regulatory  authorities, and it is required that these documents have PDF Version  1.4, are linearized, etc. In a plug-in we change the document properties accordingly. This used to work fine with Acrobat versions from 6 to 9. Then came Acrobat X.
We detected the problem with a document created with Acrobat PDFMaker 10.0 for Word: a very simple 1-page 3-lines document with no Acrobat X features.
When using Acrobat X, after calling PDDocSaveWithParams, the PDF version was not changed as required. (We check this calling PDDocGetVersion from the plugin after saving.)
Doing the same conversion with Acrobat 9 seemed to be OK: PDDocGetVersion reported PDF Version 1.4.
But when opening the converted document in Acrobat X, it still reported "PDF Version: 1.7 Extension Level 8 (Acrobat X.x)".
Opening it in a text editor showed that the header was "%PDF-1.4", but it still had "<</Extensions<</ADBE<</BaseVersion/1.7/ExtensionLevel 8>>>>..."
With Acrobat 8 and below, the version could not be downgraded, but this was reported correctly.
Downgrading the version directly via the "Optimize" function of Acrobat X worked.
I could not test Acrobat 9, since I have no Professional version available.
In Acrobat 8 Prof, I saw the message "This file appears to use a new format that this version of Acrobat does not support.", and the "Optimize" function was disabled.
Now I have the following questions:
(1) Is it a known problem that PDDocSaveWithParams does not downgrade the version with Acrobat X ?
(2) Is it a known problem that PDDocSaveWithParams does not downgrade correctly with Acrobat 9 ?
(3) Is it a known problem that Acrobat9 wrongly reports the PDF Version of the document, in this case ?
(4) Why is downgrading (or optimizing) disabled for Acrobat 8 and below ?
Thank you !

Answer 1

Remember that as of PDF 1.4, the version number in the PDF header can be overridden via a /Version key in the /Catalog dictionary.  In addition, the presence of an /Extension dictionary (ISO 32000-1) will also override the header version. 
The header version is JUST A HINT - it is NOT a guarantee of any sort.
Based on both of the above, neither of your "bugs" are bugs. 
Acrobat 9 (and I assume X as well) are reporting correctly. If you have a PDF that you believe IS being reported incorrectly, please post! 
If the Extensions dict is present, the Save command will NOT override it since it takes precedence.