How to install mbstrings:
- log in as root to your SSH
- fire off these commands:
1.yum install php-mbstring
2. echo 'extension=mbstring.so' >> /usr/local/lxlabs/ext/php/etc/php.ini
3. /etc/init.d/lxadmin restart
- restart your vps (optional)
Note: this was tested on my VPS (centos-5-i386-lxadmin)