数据库启动错误,ORA-01089: immediate shutdown in progress

ALLSTARS_ORACLE

今早一来数据库不能进去了，出现ORA-01089: immediate shutdown in progress - no operations are permitted错误
数据是晚上1：30关机备份的，关闭时不能正常关闭 (shutdown immediate ),alter_log 日志中出现如下信息：

Tue Oct 12 01:30:46 2010
Shutting down instance: further logons disabled
Shutting down instance (immediate)
License high water mark = 11
All dispatchers and shared servers shutdown
Tue Oct 12 01:30:52 2010
ALTER DATABASE CLOSE NORMAL
Tue Oct 12 01:30:53 2010
SMON: disabling tx recovery
SMON: disabling cache recovery
Tue Oct 12 01:30:55 2010
Shutting down archive processes
Archiving is disabled
Archive process shutdown avoided: 0 active
Thread 1 closed at log sequence 1433
Successful close of redo thread 1.
Tue Oct 12 01:30:55 2010
Completed: ALTER DATABASE CLOSE NORMAL
Tue Oct 12 01:30:55 2010
ALTER DATABASE DISMOUNT
Completed: ALTER DATABASE DISMOUNT
ARCH: Archiving is disabled
Shutting down archive processes
Archiving is disabled
Archive process shutdown avoided: 0 active

我知道start force 可以启动，但这诒标不治本，请大兄弟们帮帮我，跪谢！！！！