I just built a new machine and installing Acrobat was last step in process. Am running Thinkpad X210 with 10.10 64-bit. I've always been able to reliably open PDFs inline from the web; however, when I launch a PDF, the main Firefox panel goes either white, completely black, or white with black diaganol streaks.
Perhaps this is video related... Here's what I have chipset wise
VGA compatible controller: Intel Corporation Core Processor Integrated Graphics Controller (rev 02)
I'm certainly not wed to Acrobat, but I do want to have Firefox with inline PDFs from web.