In the Adobe Reader and Acrobat 11.0.03 patch, we introduced the signature field detection capability which identifies documents that the user may need to sign. Unfortunately, the signature field detection algorithm is finding some false positives and displaying the signature field detected message when it should not. We have been following the discussions on our user forums, and understand the inconvenience it has caused for some users who encountered falsely identified documents. We do apologize.
Users can quickly hide the message bar that appears for a document by clicking the icon on the left of the message bar. IT professionals and others familiar with working with registry settings can follow the instructions provided in the version 11.0.3 release notes to disable this message.
We are diligently working on improvements for the signature field detection accuracy. We are also planning to add the ability for users to turn off the signature detection message more easily. We hope to bring the improvements to you soon. Stay tuned.
9/10/13 UPDATE: The auto-detect signature field feature is disabled by default. Please see 11.0.04 Update Release for more info: http://www.adobe.com/devnet-docs/acrobatetk/tools/ReleaseNotes/11/11.0.04.html#elevenzerozerofour