<cfpdfform> gives intermittent(!) rights errors in Acrobat Reader

(This question has also been asked in the Acrobat thread.)

Using Acrobat Pro 9.1 (and the corresponding Reader 9.1 on client workstations) I have constructed a fillable PDF form and granted extended Reader rights to it.  I use this form for data-display and modification.  (Cold Fusion 8.)

The process works flawlessly on my machine, which has Reader Pro installed.  But on the Readers it will intermittently throw this error:

"This document enabled extended features in Adobe Reader.  The document has been changed since it was created and the use of extended features is no longer available.  Please contact the author for the original version of the document."

Why do I say, "intermittent?"  Because, if you reload the page ... sometimes if you simply resize the browser window ... "suddenly it works."  The document becomes fillable on Reader.  And sometimes the page appears, right from the start, as fillable.  So it's apparently a timing problem.

As I said, the computers are known to have the latest Adobe Reader installed, and not every computer acts the same ... nor does any computer act the same way with any particular consistency.  The forms always have the right data in them, and when the Reader consents to make them fillable, they perform exactly as they are intended.  (To the Adobe team's credit, CF8 makes this remarkably easy to do...)

I can say with certainty that the underlying document (on the server) most definitely is not changing, because it has been made read-only to CF just as a precaution.  I also know that the clocks on all computers are synchronized.  So, I think, a lot of "sensible" causes for the problem can be eliminated ... leaving only the "nonsensical" ones, perhaps.  I'm really looking for a work-around.

I have fiddled with cache-control headers (would like to know more about this...) just because I am grasping at straws now, but with no apparent effect.

Any assistance would be greatly appreciated.

(Heh... I'd attach the "cfm" but ... go figure ... the forum software won't allow the "cfm" or "cfc" or "zip" file-types!)