The problem is that Apple's built-in viewer, Preview, doesn't display the contents of Acrobat Forms. In Preview, you can see the empty form but none of the data filled-in. You have to use Adobe Reader. Moreover, if you want Safari to open the files in Adobe Reader by default instead of Preview you must set the default application for PDFs in the Finder.

Once the fix has been applied, Safari will honor that setting and any PDF files downloaded will be opened with Reader instead of Preview.

Here is the play-by-play in case you need more detailed instructions:

1. Switch to the the Finder, (click the smiley icon in the Dock).

2. Locate any file whose name ends with .pdf.

3. Select the file (click ONCE on it to highlight it).

4. In the File menu, select 'Get Info' (you can also use the keyboard shortcut Command-I)

5. Reveal the 'Open with:' section of the window. (The Info window is divided into several sections which can be revealed or hidden using the triangle widget on the left hand side of the window. Use the triangle to make sure the 'Open with:' section is shown.)

6. Change the 'Open with:' pop-up menu from Preview to Acrobat Reader

7. Click the 'Change All...' button, and click the 'Continue' button when you are prompted to confirm the changes.