Unable to install

I have just downloaded the new 2008 version 1.8  for joomla 1.5

I uninstalled the 1.6 version tried to install the new updated one and i get the following error message

JInstaller::install: SQL Error. DB function failed with error number 2006
MySQL server has gone away SQL=DROP TABLE IF EXISTS jos_sef_config;
SQL =
DROP TABLE IF EXISTS jos_sef_config;Component Install: SQL error or missing or unreadable SQL file. DB function failed with error number 2006
MySQL server has gone away SQL=DROP TABLE IF EXISTS jos_sef_config;
SQL =
DROP TABLE IF EXISTS jos_sef_config;

any help is appreciated

MySQL server has gone away?
Looks like your server troubles.