First : gcc44 is not an update for "gcc 4.1.2".
You can have as many versions of gcc as you want,
installed at the same time :
Default el5 compilers "gcc-c++" "gcc44-c++" "compat-gcc-34-c++"
# yum install gcc44-c++
... And you have a functional /usr/bin/gcc44
Using the extra compiler, example :
export CC=gcc44 CXX=g++44 && <other-command>.