Can you be a bit more specific?
What exactly do you mean by “Advanced Update” and “it collapses the character set”? At what point during the upgrade?
Usually problems like this are caused by a wrongly set character set for the database connection.
Maybe check the file core/config/config.inc.php to see if the variables $database_connection_charset and $database_dsn are correct.
The dtabase_connection_carset is latin1 before setup the dsn charset is also latin1. Should this be changed before to UTF_8? This has always worked with previous updates.