I also have this problem. I am using Firefox 10.0.2 with Windows Vista. Chrome has no problems displaying pdf files. I have reinstalled Adobe Acrobat Pro 9.0 and checked for all updates. Still Firefox will not display pdf files.

mtnharry (or anyone else with this problem) maybe this will help:

The Adobe Acrobat plugin has crashed

You can get this error when both Adobe Reader X and Adobe Acrobat are installed. You can resolve the problem as follows:

1. Open the Adobe Reader X application
2. Go to Edit -> Preferences
3. Under Categories (on the left) select General (near the top)
4. Click the button Select Default PDF Handler (at the bottom)
5. Under "Select Adobe Product", open the drop-down menu and click "Adobe Reader X".
6. Click "Apply", then close Adobe Reader X

Ref: http://forums.mozillazine.org/viewtopic.php?p=11654747#p11654747

I have this problem, and I don't use the Reader. I have the actual Adobe Acrobat 9.0 program. I have to use Explorer if I want to read any pdf files on the internet. Why can't Firefox fix this? It doesn't seem to help to send the crash report, I've sent at least 30 or more.