I ran into the same problem on windows. There was a setting in adobe reader that was causing that. Sorry but I don't remember what it was.
Thanks. Adobe Reader on the offending computer shouldn't be any different from our other computers but I will check it out, nevertheless.Preferences§1234567890-=BackspaceTabqwertyuiopReturncapslockasdfghjkl;'\shift`zxcvbnm,./shiftaltaltPreferences