Hi, Niall
Still there is an error.
I set the function as you said. But it's same.
There is no error when the file is opend by Acrobat pro 9.x
But by Acrobat Reader X, there is an error.
In detail, when I open the file, I can input the password.
And then, if the password is not correct, I can input it again.
but if the password is correct, the error message appeared.
I guess the security function is supported function but there is a kind of version issue.
Now, I'm using Acrobat Pro 9.x and Acrobat Reader X.
Have you ever uesed the security function? If so, let me know how I can set the password or set the other options.
Thanks.
Jaeho