How are you validating the signature? This appears similar to behavior I've recently noted in Acrobat X and XI.
There seem to be two common methods available for validation:
1. Opening the signatures tab and clicking "Validate All".
2. Clicking the signature box to open the "Signature Validation Status" window.
If you use the first option, you should not get the "subsequent changes" warning. Using the second option appears to cause a property of the signature field to change, resulting in the error.
Thanks for your reply.
Could you please suggest the possible solution as still the miscellenious changes is showing in the form.
With the signature panel open, you may also try the "Compare signed version to current version" function. (Click the gears icon to the left of "Validate All" and select that from the menu.) If you're lucky, that may show what has changed. If you're unlucky the summary will say "pages are identical".
Otherwise, if using only the "validate all" method from my first post didn't work, diagnosis is more difficult. In case changes may have been saved into the form you are experimenting with, I suggest testing with a new form that you have saved immediately after signing and before any attempts to validate.
Note: I am assuming the following:
1. Your workflow does not involve making any corrections/alterations to the document after signing,
2. The form you are using is the same as with Acrobat 8,
3. The signatures validated in Acrobat 8 without the issue you have now.