Ubuntu 10.04的PHP版本是5.3，兼容性问题一堆，要换回稳定的5.2，这里的方法是安装9.10的PHP 5.2包，其他方法参考底部链接。
操作
sudo gedit /etc/apt/sources.list.d/karmic.list
deb http://archive.ubuntu.com/ubuntu/ karmic main restricted universe multiverse
deb-src http://archive.ubuntu.com/ubuntu/ karmic main restricted universe multiverse
deb http://archive.ubuntu.com/ubuntu/ karmic-updates main restricted universe multiverse
deb-src http://archive.ubuntu.com/ubuntu/ karmic-updates main restricted universe multiverse
deb http://security.ubuntu.com/ubuntu karmic-security main restricted universe multiverse
deb-src http://security.ubuntu.com/ubuntu karmic-security main restricted universe multiverse
sudo gedit /etc/apt/preferences.d/php
Package: libapache2-mod-php5
Pin: version 5.2.10*
Pin-Priority: 991
Package: libapache2-mod-php5filter
Pin: version 5.2.10*
Pin-Priority: 991
Package: php-pear
Pin: version 5.2.10*
Pin-Priority: 991
Package: php5
Pin: version 5.2.10*
Pin-Priority: 991
Package: php5-cgi
Pin: version 5.2.10*
Pin-Priority: 991
Package: php5-cli
Pin: version 5.2.10*
Pin-Priority: 991
Package: php5-common
Pin: version 5.2.10*
Pin-Priority: 991
Package: php5-curl
Pin: version 5.2.10*
Pin-Priority: 991
Package: php5-dbg
Pin: version 5.2.10*
Pin-Priority: 991
Package: php5-dev
Pin: version 5.2.10*
Pin-Priority: 991
Package: php5-gd
Pin: version 5.2.10*
Pin-Priority: 991
Package: php5-gmp
Pin: version 5.2.10*
Pin-Priority: 991
Package: php5-ldap
Pin: version 5.2.10*
Pin-Priority: 991
Package: php5-mhash
Pin: version 5.2.10*
Pin-Priority: 991
Package: php5-mysql
Pin: version 5.2.10*
Pin-Priority: 991
Package: php5-odbc
Pin: version 5.2.10*
Pin-Priority: 991
Package: php5-pgsql
Pin: version 5.2.10*
Pin-Priority: 991
Package: php5-pspell
Pin: version 5.2.10*
Pin-Priority: 991
Package: php5-recode
Pin: version 5.2.10*
Pin-Priority: 991
Package: php5-snmp
Pin: version 5.2.10*
Pin-Priority: 991
Package: php5-sqlite
Pin: version 5.2.10*
Pin-Priority: 991
Package: php5-sybase
Pin: version 5.2.10*
Pin-Priority: 991
Package: php5-tidy
Pin: version 5.2.10*
Pin-Priority: 991
Package: php5-xmlrpc
Pin: version 5.2.10*
Pin-Priority: 991
Package: php5-xsl
Pin: version 5.2.10*
Pin-Priority: 991