mysql with 1.9.2 query: wrong argument tile Mysql (expected Struct) TypeError

[Love4llamas]

Using rvm, this works fine in 1.8.7 but fails in 1.9.2 with query:
wrong argument tile Mysql (expected Struct) TypeError

require 'mysql'

mysql_connection = Mysql::new(@mysql_host, @mysql_user,
@mysql_password, @mysql_db)
mysql_connection.query("delete from mytable")
mysql_connection.close

Any suggestions would be appreciated!