Comment 42 for bug 521533

I also stumbled about the fact that it seems to be impossible to have multiple instances of the same filled in form under the same file name and got the impression that "Save as..." does not work. After some experimenting I found out the problem with "Save as...":

There's two places where form data is stored: .kde/* and the pdf-file itself. Data is always saved to .kde/* (attached to filename?). If you use "Save as" it's also stored to the file. The problem is that this is not visible to the user and that .kde/* seems to have precedence. If you want to fill the same form twice you can easily run into problems:

Case a: Since form data is visible after closing, reopening, or moving the file, the user assumes that it's stored inside of the pdf. To fill a form a second time he copies the filled in form into a new location and changes the necessary data. Everything seems to work, but if he reopens the original file all it's data is changed to what he entered in the new place.

Case b: The user is aware that data is stored in the file only if he used "Save as". After filling the form the first time he uses "Save as". To fill the form a second time he copies the filled in form into a new location and changes the necessary data and uses "Save as" again. Now different data is saved in both versions of the file. But if he opens version 1 again, he sees the changes he did in version 2. The reason for this is that by changing version 2, the data in .kde/* is changed and this seems to have precedence when viewing version 1. If you delete th corresponding file in .kde/* you see what's stored in the file.

In both cases the user seems to have lost data. In a) this is true, in b) his data is just not visible.