Starting with X.org release of the X environment, the US-International, with deadkeys, on UTF-8, got some weird behaviour regarding some key combos. One of the is '+c, with used to produce a c. I say it is weird because it is not the expect behaviour for people who came from XFree86+ISO-8859-1 environment. Now, with the default mapping, you will get a c instead (that is a “c-acute” for the UTF-8 impaired). On this new mapping, you need AltGr+,+c, which is kind of cumbersome.
The way to fix it is to edit the file (CentOS 4):
On CentOS 5, use the file:
Replacing the occurences of the said c with c, for both lower and uppercase.
That, however, might not be enough for GTK based applications (like Firefox). For that, you will also need to edit (CentOS 4):
or, on CentOS 5:
On that file, find the line configuring “xim”, and adding the “en_US” and “en” locales there, ending up with something like this:
"/usr/lib/gtk-2.0/2.4.0/immodules/im-xim.so" "xim" "X Input Method" "gtk20" "/usr/share/locale" "ko:ja:th:zh:en_US:en"
Again, on CentOS 5, it is a bit different:
"/usr/lib/gtk-2.0/2.10.0/immodules/im-xim.so" "xim" "X Input Method" "gtk20" "/usr/share/locale" "ko:ja:th:zh:en:en_US"
With that, you can now restart X, and have your old behaviour for '+c again.