[Serusers] postgres and mysql

Hello, I'm using postgres for authentication and accounting since a few days and it's working perfect. But I'm wondering why I have to load the mysql.so - Module, too. If not (commented), I get the following error: 0(0) Maxfwd module- initializing 0(0) PG[238] db_init entry 0(0) PG[193] str2valp got int 2 0(0) PG[274] db_close entry textops - initializing 0(0) bind_dbmod: Module mysql does not export db_use_table function 0(0) ERROR: uridb_db_bind: unable to bind to the database module 0(0) ERROR: uri_db:mod_init(): No database module found 0(0) init_mod(): Error while initializing module uri_db ERROR: error while initializing modules This error also appears, if I don't have installed/running a mysql server. It seems very strange... because all the data is saved correctly in my postgresql-database. Why do I need the mysql-module then? OK, one additional information. To specify my database I use the following command: modparam("acc", "db_url", "postgres://admin:password@localhost:5432/AAA") If I use "sql://" instead of "postgres://" there appears the same error like above. Any ideas? Thanks! Sebastian