The following appears to have I solved my problem with Safari 5.1.5, 5.1.6 and 5.1.7. I also have Adobe Acrobat Pro 9 installed.
- Follow mbuffy's post dated May 10, 2012 directly above, and
- Do NOT allow Adobe Acrobat Pro 9 to perform the "repair" the missing Adobe PDFViewer Plug-in when the window pops up and offers to repair Adobe PDFViewer Safari Plug-in. If Adobe does the "repair," then I can not view .pdf web pages in Safari or Firefox.
FYI, cmmartin0275 posted the following on Sep 8, 2011 in a discussion of "Missing PDF Pluggin" at https://discussions.apple.com/thread/3291814?answerId=16119130022#16119130022:
"Just FYI to anyone with this problem...this is straight from Adobe's website.
"Adobe Reader plug-in and Acrobat plug-in are not compatible with the Safari 5.1 browser, which will ship with Mac OS X 10.7 and for 10.6 in July. Adobe Reader and Acrobat will continue to work as standalone applications on Mac OS X 10.7 and 10.6, and will render PDF documents outside of the browser. In addition, Safari 5.1 renders PDF documents natively. However, the Adobe Reader and Acrobat plug-ins will not function as expected in LiveCycle and Acrobat workflows that require either plug-in to render PDF documents in Safari 5.1."
They also go on to say they hope to have a solution or work around before the end of 2011..."
Thanks for the help.