ORA-01606 oracle10g 10.2.0.5

my solaris 10 and oracle10g 10.2.0.1 rac (2 node ) is ok,

but after i update roracle dabase to 10.2.0.5 ,

only one rac node can start ,

next  whill show:

SQL> startup nomount;

ORACLE instance started.

Total System Global Area 8589934592 bytes

Fixed Size                  2065848 bytes

Variable Size            1342184008 bytes

Database Buffers         7096762368 bytes

Redo Buffers              148922368 bytes

SQL> show parameter gc;

NAME                                 TYPE

------------------------------------ ----------------------

VALUE

------------------------------

gc_files_to_locks                    string

gcs_server_processes                 integer

24

SQL> alter database mount;

alter database mount

*

ERROR at line 1:

ORA-01105: mount is incompatible with mounts by other instances

ORA-01606: gc_files_to_locks not identical to that of another mounted instance

i confirm two nodes parameter is same !