if you have setup a new server and suddenly you find out that .htaccess configuration file is not working on your here is a quick solution to fix it. There might be 2 issues with your web server which could have caused this problem. 1. Make sure AccessFileName set to .htaccess To check this open httpd.conf or apache2.conf depending on your OS and search for AccessFileName and make sure it is set to .htaccess nano /etc/httpd/conf/httpd.conf if you dont have nano you can install nano yum install nano 2.Make sure users are allowed to use .htaccess file To check this open httpd.conf or apache2.conf depending on you OS search for AllowOverride and make sure it is set to AllowOverride All nano /etc/httpd/conf/httpd.conf also make sure you restart your apache after applying changes service httpd restart

I found this problem on my new CentOs 64 bit machine. I think the solution i found for it will work both on 32 bit and 64 bit machines. The trick is to get latest mysql from repo and install all extensions you need separately and it will work fine.
First thing is to get the latest repository for php. The repository i found was listed on php.net itself so i think its best to use that everytime.
the first thing is that create a temp folder anywhere you like best place is
/usr/src  (CentOs path) this path can be different on different linux os.
now type these are 3 separate commands :
wget http://dl.iuscommunity.org/pub/ius/stable/Redhat/5/x86_64/ius-release-1-2.ius.el5.noarch.rpm
wget http://dl.iuscommunity.org/pub/ius/stable/Redhat/5/x86_64/epel-release-1-1.ius.el5.noarch.rpm
rpm -Uvh ius-release*.rpm epel-release*.rpm
Once you have done that a repository is automatically created on your linux machine to see whats in the repository
yum list | grep -w \.ius\.
to install new php you have to first remove the previous version
yum shell
remove php-gd php-cli php-odbc php-mbstring php-pdo php php-xml php-common php-ldap php-mysql php-imap
install php52-gd php52-cli php52-odbc php52-mbstring php52-pdo php52 php52-xml php52-common php52-ldap php52-mysql php52-imap
transaction solve
transaction run
NOTE: It is *very* important that you run ‘transaction solve’ to ensure all dependencies are being met with the new packages. Removing packages with unmet dependencies in Yum can lead to a nightmare of packages being removed.
thats it your new php has been refreshed and now mysql.so will be there.