[CDBI] Class::DBI with multiple db connections

i'm trying to use Class::DBI with several db connections, but i'm
finding that i have to alter the set_db() method from:

sub set_db {
	my ($class, $db_name, $data_source, $user, $password, $attr) = @_;

	# 'dbi:Pg:dbname=foo' we want 'Pg'. I think this is enough.
	my ($driver) = $data_source =~ /^dbi:(\w+)/i;
	$class->__driver($driver);
	$class->SUPER::set_db('Main', $data_source, $user, $password, $attr);
}

to:
sub set_db {
	my ($class, $db_name, $data_source, $user, $password, $attr) = @_;

	# 'dbi:Pg:dbname=foo' we want 'Pg'. I think this is enough.
	my ($driver) = $data_source =~ /^dbi:(\w+)/i;
	$class->__driver($driver);
	$class->SUPER::set_db($db_name, $data_source, $user, $password, $attr);
}

for it to work correctly. With this mod i can then use set_sql() with
a handle name and it all works.

I'm I missing something here?