If you do need an alternative, though, then Adobe does offer a compatible plug-in with its latest Adobe Reader for OS X however, those who have older versions of Adobe's CS suite or Acrobat Pro program may inadvertently install the plug-in when either repairing their current installation or reinstalling the program from scratch, steps that might commonly be done after upgrading OS X. Since Safari provides built-in PDF compatibility, for most people there has been no real need for an alternative PDF viewer plug-in. This problem is not widespread by any means, and seems to be rooted around the user installing an incompatible Adobe PDF viewer Web browser plug-in. When you might expect to see the standard arrow as the mouse pointer, the cursor will instead look like a crosshair or another alternate cursor. After upgrading Mountain Lion, you might find odd problems such as Safari crashing, or the system not showing the appropriate cursor at times, either in Safari or in other programs like Microsoft Office.
