[CentOS] Manual update

Hi all,

I have a problem :).

On my CentOS workstation, I had      glib2-2.4.7-1 installed.
This is the last version which is provided by the CentOS distribution
However, I need to install a software which requires an higher glib2 
version so :

I took the source of glib2-2.8.4-1 on the gtk+ web site and creates the 
rpm installation file with "chkinstall"
I obtained the glib2-2.8.4-1.i386.rpm file
Then I execute yum to update the glib2 package  :

yum localupdate glib2-2.8.4-1.i386.rpm

And know, I have a lot of problems. Surely because some library files 
where overwritten with the newer version files (Right or wrong ?)....

Is there a way to recover the problem ? (Now, I can't launch a terminal 
under gnome)

Well, I have broken the distribution and I feel that I will have to 
reinstall it.

For the next time that I will try to update a package manually :
Is there a safe way to update manually the glib2 library without 
crashing all the distribution ?
Or is there a way to install the latest version of glib2 in order to 
have the two libraries versions installed (glib2-2.4.7-1 and 
glib2-2.8.4-1)?
or something else ?????

Thank you for your answers,

Jean LEE