Plus sign on keyboard opens menu

I guess my cat walked across the keyboard or something but I am spoiled to hitting the plus sign on my keyboard and having the text/pictures enlarge. Now it just opens a pop-up menu. I couldn't find another thread that addressed this problem. I am using Opera 12.13 version, build 17.34 on Fedora release 12 Laughlin, kernel 2.6.35.14-106.fc14.i686; Gnome 2.32.0. I really miss my enlarge feature -- any ideas? I am not particularly techie.