If that does not help, then I would uninstall Acrobat and re-install. Oftentimes, it's not Acrobat that is crashing, but a plug-in. If you have any 3rd party Acrobat plug-ins installed, I would remove them and see if that helps with the number of crashes. Use 'Disk Utility' and repair your permissions.

Unfortunately, on the Mac we don't have the 'Repair' function that is available to user of the Windows version.