ERROR 1010 (HY000) mysql 5.5.19

ERROR 1010 (HY000): Error dropping database (can't rmdir '.\test', errno: 13) 

[root@xinnet5519 mysql]# ./bin/mysql -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 10
Server version: 5.5.19-log MySQL Community Server (GPL)

Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| test |
+--------------------+
4 rows in set (0.00 sec)

mysql> drop database test;
ERROR 1010 (HY000): Error dropping database (can't rmdir './test/', errno: 17)
mysql> show warnings;
+-------+------+------------------------------------------------------------+
| Level | Code | Message |
+-------+------+------------------------------------------------------------+
| Error | 1010 | Error dropping database (can't rmdir './test/', errno: 17) |
+-------+------+------------------------------------------------------------+
1 row in set (0.00 sec)

mysql> exit
Bye
[root@xinnet5519 mysql]# ll

[root@xinnet5519 data]# cd test/
[root@xinnet5519 test]# ls -all
total 8
drwxr-xr-x 2 mysql mysql 4096 Jan 17 16:49 .
drwxr-xr-x 5 mysql mysql 4096 Jan 18 16:29 ..
-rw-r--r-- 1 mysql mysql 0 Nov 23 23:28 .empty
[root@xinnet5519 test]# rm -rf .empty
[root@xinnet5519 test]# /usr/local/mysql/bin/mysql -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 11
Server version: 5.5.19-log MySQL Community Server (GPL)

Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> drop database test;
Query OK, 0 rows affected (0.00 sec)