is there any error for my postgresql installation?

["中和刘" <minxinjianxin@gmail.com>]

here is a latest log messages for my newly installed postgresql server
2008-12-06 12:33:08 HKT LOG:  could not load root certificate file
"root.crt": no SSL error reported (1)
2008-12-06 12:33:08 HKT DETAIL:  Will not verify client certificates. (2)
2008-12-06 12:33:08 HKT LOG:  could not create IPv6 socket: Address
family not supported by protocol (3)
2008-12-06 12:33:09 HKT LOG:  database system was shut down at
2008-12-06 12:32:18 HKT
2008-12-06 12:33:09 HKT LOG:  autovacuum launcher started
2008-12-06 12:33:09 HKT LOG:  database system is ready to accept connections
2008-12-06 12:33:09 HKT LOG:  incomplete startup packet (4)

is (1) a error? what should i do?
what does (2) mean? is it normal?
is (3) ok?
is (4) a error? what should i do?

thanks