Post MOUNT stage DB Taking looooooooong time to Open

System = SunOS
Node = czssd1007
Release = 5.10
KernelID = Generic_127111-09
Machine = sun4u
BusType = <unknown>
Serial = <unknown>
Users = <unknown>
OEM# = 0
Origin# = 1
NumCPU = 24

SQL> select VERSION from v$instance;

VERSION
-----------------
10.2.0.4.0

SQL> select count(1) from v$datafile;

  COUNT(1)
----------
       108

SQL> select round(sum(bytes/1024/1024/1024)) GB from dba_data_files;

        GB
----------
        53

SQL>

* DB was cleanly shutdown. (No Abort)