PLSQL无法远程连接，一连接就死掉

ORACEL 11g tnsnames.ora配置文件如下：
---------------------------------------------
ORCL=
  (DESCRIPTION_LIST=
    (DESCRIPTION=
      (ADDRESS=
        (PROTOCOL=TCP)
        (HOST=localhost)
        (PORT=1521)
      )
      (CONNECT_DATA=
        (SERVICE_NAME=orcl)
      )
    )
   )

APPOUT =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = 10.16.71.61)(PORT = 1621))
    (CONNECT_DATA =
      (SERVICE_NAME = app)
    )
  )
APPOUT2 =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = 10.16.71.61)(PORT = 1621))
    (CONNECT_DATA =
      (SERVICE_NAME = app)
    )
  )
EXTPROC_CONNECTION_DATA =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1))
    )
    (CONNECT_DATA =
      (SID = PLSExtProc)
      (PRESENTATION = RO)
    )
  )
--------------------------------
sqlnet.ora配置如下
------------------------------------

SQLNET.AUTHENTICATION_SERVICES= (NTS)

NAMES.DIRECTORY_PATH= (TNSNAMES, EZCONNECT)
--------------------------------------------------

本地数据库连接不存在问题(scott/tiger),远程tnsping也没有问题

TNS Ping Utility for 32-bit Windows: Version 11.2.0.1.0 - Production on 23-5月 -
2011 14:15:12

Copyright (c) 1997, 2010, Oracle.  All rights reserved.

已使用的参数文件:
D:\oracle\product\11.2.0\dbhome_1\network\admin\sqlnet.ora

已使用 TNSNAMES 适配器来解析别名
尝试连接 (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = 10.16.71.61)(PORT = 1
621)) (CONNECT_DATA = (SERVICE_NAME = app)))
OK (110 毫秒)

但是用PLSQL连接APPOUT数据库的时候，PLSQL就一直死掉，不知道是什么原因

sqlplus登陆的时候也是死掉的，没得反应。

现在的结果：我把oracle11g卸载了，重新装上oracle10g，一切问题迎刃而解，我很困惑，因为这个问题已经让我苦思不解两天了，现在突然这样轻而易举的解决了，心里还是有点失落感的。
重装算了