LaTeX.org

If you mean that you TeXMaker stop doing the "special" accents like á,à,ã... and the only thing you can type is ~a,'a, etc. I guess it's a SCIM config got wrong. You should install the ibus-qt4 package to fix problem:

Debian/Ubuntu:
$>sudo apt-get install ibus-qt4

Fedora equivalent:
$>yum install ...