Adobe PDFViewer for Mac OS X does not run correctly on a system that doesn't meet the following requirements:
Acrobat/Reader 8 supports viewing PDF files inside Safari windows on Mac OS X, and runs only on Mac OS X 10.4.3 and later. It does not support any other browser (such as Firefox and Opera).
Note: If you don't have Acrobat or Adobe Reader, then Safari running in 10.3.9 or later shows PDFs inside its window using the Mac OS X native PDF support; this setup does not support many Adobe PDF workflows (such as the Collaboration feature or many Forms and Security features).
Drag the Acrobat application folder from the CD (or disk image) to the Applications folder to install Acrobat. The first time you start Acrobat you are prompted to accept the end user license agreement (EULA) and register Acrobat. After you accept the EULA, Acrobat runs a self-healing procedure that checks for any Acrobat components that need to be installed in other applications. The self-healing process installs the Adobe PDFViewer plug-in file, which is used by Acrobat to view PDF files in the Safari browser on Mac OS X. This file is installed in the Library/Internet Plug-Ins folder.
If you updated or reinstalled your copy of Safari to view PDF files, then do the following:
In Acrobat, choose Help > Detect And Repair and select Adobe PDFViewer.
The first time you start Acrobat or Adobe Reader 8 on Mac OS X, it automatically installs itself as the default PDF viewer for Safari. To turn off this setting, start Acrobat or Adobe Reader and go to Preferences > Internet. Deselect the Display PDF in browser option, which causes the PDF to display inside the Safari window using its native PDF viewer.
The following are known issues in Acrobat 8:
If you delete the AdobePDFViewer files, they self-heal when you start Acrobat again. You can also fix Safari manually by choosing Help > Repair Acrobat Installation.