Acrobat v9.3.2 Won't Save PDF Files On W7 64 Bit

Question

I have a dilemma that needs to be solved.  I have a new Windows 7 64 bit system with several terabytes of legal documents stored locally, mostly in PDF.  After loading Adobe Acrobat Standard v9.3.2 I find that while I can open PDF documents, I can only save edits/highlights/comments only once.  However on all subsequent edits and save attempts Adobe delivers the message:
"The document could not be saved.  The file may be read-only, or another user may have it open.  Please save the document with a different name or in a different folder".  I no for a fact that the file is not open elsewhere and if I view the security properties of the file it does not show as read-only.  If I save the document with a new file name it behaves correctly just once, then begins delivering the same error message as the original PDF on all subsequent saves.
In addition to the built-in Windows accounts there is only one user account on the W7 system, it has password protection and administrative privileges.  The PDF files that cannot be saved are all owned by this account and the account presumably has "full privileges".  Further, the PDF documents themsvelves have "no security" and allow for editing/highlighting/commenting.  It is important to add that many of the same PDF documents I'm trying to edit were easily edited and saved on a previous 32 bit Windows XP Pro system which this sytem replaced.  Moreover, on a seperate 32 bit Windows 7 laptop and the 32 bit Adobe Acrobat Standard v9.3.2. these same PDF files stored on a network drive have no difficulty performing all the edit and save functions.  However, if a sample PDF document stored on the local drive of the 64 bit W7 system is shared and accessed directly by the 32 bit W7 laptop system, the laptop/Adobe Standard will deliver the same error trying to editing and save the image stored on the 64 bit Windows 7 system.
I have tried running Acrobat on the 64 bit W7 desktop as "administrator" but the problem persisted.
My Acrobat Standard indicates there are no updates available.
I've pretty much exhausted everything I know to look for and I am stuck.
I hope someone can offer some insight to this.
Thanks in advance,
Sandy

Answer 1

I believe I may have found the problem and potential fix or workaround for the problem described in my original post.
Windows 7 has a feature in Windows Explorer that will if enabled show a file preview image in the rightmost pane when a file is selected or moused-over.  If one selects an Abobe PDF document to launch Adobe Acrobat will launch in a seperate window while the Windows Explorer pane will show a thumbnail sized image of the first page of the PDF document in the Windows Explorer pane.  The explorer window may even be behind the Acrobat application so once one is looking at the full document in Acrobat they may not even notice the thumbnail image in Windows Explorer.
On my setup, when this would happen I could edit a PDF document and save the PDF only once, but any further save would fail. Apparently the thumbnail in Windows Explorer is enough to make Acrobat believe the file is already open, or open by another user.
One workaround is that once Adobe Acrobat is launched explicitly look for and close the Windows Explorer showing the PDF thumbnail.  One might also accomplish the same by moving the mouse over a different file so the thumbnail of the open PDF is not showing, or to turn off the preview function in Windows 7 Explorer altogether.  I haven't yet tried the latter.
Acrobat is the only application on my W7 Pro system that doesn't play well with Windows preview mode.  My MS Office apps have no difficulty saving even while showing thumbnails in the preview pane.
I hope this might be helpful to anyone else experiencing this problem.