First off, do you have the mysql-dev package installed? As for whether or not it will run with mysql 5.0.22, it can, but it's tricky. The makefile for the mysql module doesn't look everywhere for the libmysqlclient libs when it's compiling. It expects the libs to be in a particular place, and if they're not there, it ignores the libpath, compiles ANYway, and they just fails to work once you start up SER. It gives NO errors on compile, which makes it utterly difficult to track down. The latest RPMs for RHEL/CentOS from the MySQL community site place the libmysqlclient.so.X libs into /usr/lib and NOT /usr/lib/mysql as SER expects. SER will simply NOT find it in that location. What we've ended up having to do is symlinking the /usr/lib/libmysqlclient* into /usr/lib/mysql, recompile the mysql module, and install it in the correct place. Then, SER runs happily and readily without weird errors. Also note that there is a patch that must be applied to use MySQL 5.0.X for SER 0.9.6 see http://www.iptel.org/faq/why_does_my_mysql_5_0_x_connection_time_out_when_u… N. roayu wrote: